He CAME in me need info

Brooke • I`m 23. Louisiana born & raised.
I keep up with my period with this app for the past 4-5 months it has been on point or maybe a day or two off... Well I'm now a week late and 3 days ago my SO & I  made love a couple times that night and he came inside me... Can that get me pregnant now since I was suppose to be on my period and it still hasn't come. And yes I took a pregnancy 2 days after I was late and came back negative. But now I'm starting to get worried about the other night. Any info is appreciated to the fullest.