Anyone with thoughts!!! please!

I've only had sex a couple of times with one person who I really trust. We always use a condom and withdrawal method to be careful, and I really trust that if anything happened he would tell me. But, my period is 4ish days late right now and I'm very scared. I took a stick pregnancy test and it came out negitive but I know the earlier on the more likely for a false negitive! I'm young so I get it could just be a irregular period, and the stress from being scared may just be pushing it back more! Anyone with any thoughts please share!!! Anything is helpful!!! 
Thanks <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">eve</a> community!! 
(I also posted something very similar on the other pregnancy group, so if you do have thoughts you're willing to share, either one is good!)