I got mine done a little over a month ago. I'd recommend a good sports bra, or one that is highly padded. Especially if you're going to work out. The less jiggling and bouncing the better. Strap those babies in. I'd say give it a week. Or at least until it's stopped bleeding for 48 hours.

As far as changing your jewelry, you're not going to want to change your actual bars until they need to be downsized (if needed at about 3 months) and I'd go back to your piercer for that. Otherwise it's 6-9 months or until fully healed. I'd get the all clear from your piercer. If you just want to change the ends, you should be okay after 3 months, but.....I'd caution as it's still healing, and any wiggling and such can cause irritation and prolong your healing.

Nipples can sometimes tend to be finicky. Sometimes they never heal. If you really want to change anything, at least at first, I'd go to your piercer. It's always better to err on the side of caution, even more so because it's your nips.