NEED ADVICE !!

I’m 19, and 27 weeks pregnant. I just had sex and after I started bleeding lightly, although I’ve never had this happen to me after sex before. I called L&D and they said

It’s normal but if i get contractions or fill a period pad full then go to emerg. I feel him moving and it’s not heavy bleeding but I’m a FTM and a little over protective and nervous.