I just lost my virginity on the 3rd of this month, it was protected. I usually always get my period on the 18th of every month, I'm waiting for it but it's extremely late, according to my PD calendar, I'm 7 days late. Yesterday I went to the clinic and did a urine test but it came out negative. I wasn't really stressed out about it until now. Does having sex the first time push my period back? Or is it season change? I have no pregnancy symptoms other than lower back pains but I don't know if that was symptoms because I had a slip disk. Right now I have a mild headache but I think thats just me because Im freaking iut So I'm a definitely confused.