I shaved last Thursday and the same day I ended up having sex and now I see little red bumps on my vagina and I don't know if it's normal or an std?

Hair removal. Most likely it is just irritated skin from shaving and then the friction of sex. I strongly recommend not shaving - the hair is there for a reason, it protects the sensitive skin of the vulva. If you absolutely must shave, use an electric clipper so you don't get micro-cuts from the razor. It is always a good idea to be checked for STDs, too, but that doesn't like like what this is.