How often do you change your scrubs and how many do you have?

I change them after every shift. I own 5 pair, washed seperate from other laundry, at least once per week.

I change my scrubs after every shift. I also keep them separtate from my regular laundry. Especially if you cared for any patients on precautions for contact and droplet, and if your scrubs got anything on them. Try to have a back up set in your bag, locker, and/or car in case of messes requiring a full change.

I have around 13+ sets with different styles and sizes. I recommend having at least 4 sets of scrubs. 1 for work, 1 back up, and 2 for the next shifts. It's also a good amount for a load of laundry. A jacket, undershirts, and leggings for under scrub pants are good if you're in cold climate or work in units that are colder (ie. ICU). With weight gain and loss it's good to have the next size as well as in case of shrinking in the wash.

If you are budgeting for scrubs and they can get expensive, I recommend starting off basic and having the back-up be basic as well starting out. If you have friends or family members that were the size and color you need, you could ask if they have any they can let you borrow or have. 2nd hand stores sometimes carry scrubs as well, but might be harder to find what you need.
If you have uniform stores nearby visit them since they can have a clearance section, sales and even member discount or health care organization discount. Another way they can be helpful is if you don't want to worry about shipping cost and if you want to try on a style sold online you'll know if it fits.
Ex: I would go to a uniform store and try on various brands, styles, and sizes and then note what ones I liked and purchase a couple sets or however many I needed then. Later, if I saw a sale online for the particular brand, style, and size, I would order them online if I didn't need them right away. You can also mix-and match scrubs to stay in your budget.

Brands: You will find that some brands are more expensive and some are cheaper depending what collection/clothing line they are in. Generally, I find Unisex scrubs to be much cheaper and more affordable. I started my nursing career path in high school and Cherokee Workwear is still my favorite with Dickies being a close 2nd. Depending on your preferences and body shape, some styles might be better, more comfortable, and even safer (ie. pant legs hemmed if you need them to prevent tripping, tops taken-in if it gets caught on things, etc.) I also love cargo scrub pants. You can never have too many pockets as long as you are organized. A couple of my favorite cargo scrub pants are Cherokee Workwear Revolution and Dickies EDS Essentials.

You want to be comfortable and for your scrubs to fit well so that you look professional, can move around easily, and have the amount of pockets and loops you need for your tools.

I'm retired now .. THANKFULLY!!❤️. However, when I Was working, they were in the laundry Every shift. But, I'm thinking maybe you're asking on style?? I'm gonna "assume " you would put them in the wash pile after Every wear. I worked mother-baby, so we supplied our own scrubs. I had about 25-30 sets ...including holiday themes. This way I wasn't limited to just a few choices. I could be 'plain' one day, and whimsical the next. When I retired, I took them to work and gave them away .. they went FAST! LOL! One of my co-workers asked if I Really wanted to give them all away? After all, I "might"want to come back or do something else in healthcare! I told her NO WAY IN HELL was I even Remotely interested in working in healthcare anymore! 45+ years was Plenty! Now 18 months later, I STILL won't come back! However, I might earn some extra 'good' money by helping my friend doing pet transports across the country!❤️. Animals are soooo much better than people these days!❤️❤️. Don't get me wrong ... I LOVED working with new moms and their babies! Getting them started out on the right foot, teaching them about themselves and their new little humans ... things we used to learn from mothers and grandmothers. Watching someone struggle desperately with breastfeeding and being able to be the 'one' who was able to find a method that worked for HER and watch her Succeed!❤️. If I could just do THAT ... it would be the "almost" Perfect job!! But, 'business' interfered with us being able to do best, what we do best.
Constant compromises, restrictions, limitations, and just all-around horrible attitudes .. ALL up and down the 'chain'. It came to a "head" one day, and enough was enough, and I put in my retirement 18 months Early! No Way was I going to even consider "complying"! What I saw one day under the microscope, with my OWN EYES is what cemented my decision. It was scary beyond belief ... and no matter what, there was no way I would participate! Best Decision Ever! Unfortunately, my predictions concerning this "c" disaster are coming to fruition.... and sadly, it's only the tip of the iceberg ... the worst hasn't 'hit' yet, and it's just beginning.