Any mommies experience this ?

I know bleeding is super common during pregnancy . But I’m 12w3d and this is the absolute first time I’ve bled . I have a UTI but I’m 5 days (out of 7) into amoxicillin. The bleeding didn’t start until after I started my antibiotics. It started off brown ,pink & now red . No cramping I can feel slight taps from baby (second) pregnancy . ER nurse said it was normal but I feel like I wasn’t given enough information. Am I overthinking this ?