Red bumps on lower belly?

Ive never had this before. A few days ago a bump appeared on a stretch mark I have. Thought it was nothing. Now, I’m noticing more and more of these mysterious bumps. They itch too!! They are all below my belly button and just appear at random and itch like crazy. I haven’t been scratching but still.

Anyone know what these are? I’m 13 weeks with my 3rd. I have an appointment Friday and will be asking but I’ve never had this on other pregnancies