Low lying placenta and sex question

Hi - so please don’t judge. I was told I may have a low lying placenta last week during a little ultrasound I had because of dehydration. Nurse said just refrain from sex until my anatomy scan next week. Well we had anal sex today- not thinking that would matter because she mentioned only the vagina. Now I’m regretting it because I’m reading online you shouldn’t do that. Needless to say, we won’t be doing that again. Anyway - how long after sex with low lying placenta did anyone notice bleeding? The bizarre thing is - we have been having sex since day 1 and I never had pain or bleeding ever. Could the nurse just be wrong?