I’m scared I can’t get pregnant


So we’ve never used condoms , pull out method has been our choice for a year now but there are times when he ejaculates in me. This month he ejaculated in me almost every time and I think I just got my period a week early today. 16 year olds accidentally get pregnant all the time!!! How come I’m not pregnant yet ?! I’m scared I can’t get pregnant now even though I’ve never had menstrual issues before ... no cysts very regular everything is looking good . And he already has a child with someone else so his swimmers are working fine .. I want to be a mom so badly .. I’m just scared .. what do u girls think