Confused?!

I had sex on April 26 so that was about 4 weeks and a couple days ago he came inside me and stuff ever since I’ve been feeling different (my body) I have irregular periods my period didn’t come back for like 7 months after my first period until March 25 -26 then on April 25-26 and it was only here for 2 days (we had sex after it left) my period is now 2 days late or maybe it’s not coming back again ? I took a total of 4 pregnancy test ever since April 28 and went to the doctors on April 29 blood test n hpt was negative maybe too early? But now my period is two days late like I said the last pregnancy test I took was two weeks ago idk what to do I’m 17 I can’t go do stuff on my own without a parent or guardian I’m so confused!