should i be worried ???

so i had sex for the first time july 10th, i was on birth control for about 19 days and we used a condom and he pulled out. I got my period the 15th of july and it seemed pretty normal. I was still kinda nervous and got a blood pregnancy test done three weeks later and it came out negative. We haven’t had sex since the first time and i did get my period after but yesterday eve said i would get my period on August 10th but i didn’t and i took my second placebo pill as well. I don’t know if i should be freaking out or if my period is just gonna show up later than eve expected?