Bleeding after fingering

Sooo I was messing around with my boo and things were getting pretty intimate. I felt like I was pretty lubricated bc the vagina part of my underwear was wet. So he slipped a finger in and did the deed. But see, he went really deep. Like I thought he lost a knuckle honestly (still talking about fingers) .. but anyway , after that was done I looked on the bed and it was little spots of blood all over his sheets . And I haven’t had sex or anything down there in a few months , so I knew i kinda figured it was me but why ??? I was so embarrassed.

Also my period is late but ever since I started college my period has been irregular and I’m starting birth control, but I’m waiting on my period to start the medication!