Period help

I got my last depo shot in feb and I didn’t get my next shot. I haven’t had a regular period yet except for some light pink/dark brown bleeding for less than a day. It has happened twice now. And then my bf came inside me for 3 days in a row and then I started heavy bleeding the next day. And I mean heavy bleeding I filled a tampon inless than 20 mins and I was having cramps. And then when I woke up the blood had stopped. I took a pregnancy test 1 week before all of this and it came out negative. I want to know if it was my period or if there’s anyway I could be pregnant?