What are these bumps?

I circled the bumps so they’re easier to see (the other bumps are moles or my piercing scar)

The bump in the dark circle near the belly button has been here the longest, the others are new. They seem to come and go... except the one near the belly button, it’s been there for 2 or 3 days.

Is it possible they’re a reaction to the oils I’ve just rubbed on my skin? (But I’ve been using the same oils for the entire 25 weeks I’ve been pregnant)

They don’t seem to itch or hurt...