What Is Happening ??? 😱😲

I'm 21 weeks and I have been itching a lot pretty much everywhere(arms,legs,stomach,and breasts) but I thought it had to do with being pregnant but I've been noticing that everywhere I've been itching there are tiny red bumps everywhere ..they are all over my stomach and breasts and the itch really really bad...what is going on? is there anything I can use to treat it ?