I am 18 years old. My last period was between 3-5 weeks ago. Me and my boyfriend have had sex everyday for the past 2 or 3 weeks and he ejaculated in me everytime. I havent had a period yet.. I always start before all the girls I work with and they all have already had their periods.. I have weird food cravings , mood swings, I feel like I cant get enough to drink, Constipated, peeing more than normal, tired a lot more, and my boobs hurt pretty bad.