Is it normal normal to star your period after intercourse?

My history with periods has been more than odd at best. Last year around October I stopped having my period and it didn't start back up until mid-spring the next year. Some cramps here and there, but I wasn't really alarmed; my diet was poor since we couldn't afford much and I just linked it with that. Then it was fairly normal until about a month ago.

My period was late, but after having intercourse with my boyfriend it started. I took it as a coincidence; the period lasted a couple days, was light, and then was done. A few days after that, after intercourse it started again and lasted a day or two. And again. And again. It looked like how it looked when you're about to end your period so I figured "Maybe it's just having trouble wrapping up". Then a day ago, it happened again but the flow was heavy, like it normally would be at the peak of a period.

Maybe it's a condition that you get when you turn into a young adult. Either way I think i'm gonna schedule a proper doctor's appointment (i'm not looking for diagnosis on the internet), but I was just curious if anyone else had an experience like this?

Is starting after intercourse normal?