Constantly paranoid about being pregnant?

So, I am CONSTANTLY paranoid about this. I have no idea why either. I'm sure I'm not the only one out there, but you know when it's you, you need reurance lol. Anyway yeah, I'm 18 and last month my period came a little later than I'm used to (I don't keep track or anything like that but I usually have a pretty good idea of when to expect it). So from then on I've been worrying. I am a virgin, I have not been fooling around in any way to worry lol, it's just that I'm stupid and I get paranoid. I've been eating so much, holy crap. But I work at the mall and I'm constantly tempted by that darn food court. Then again before I started working I was just at home and wasn't doing much to make myself hungry (other than boredom) and only ate at most 2 meals a day usually 1. But since last week I've up the intake of food (almost 3-5 meals if not more). I've been getting a little pissy lately as well, but taking photos of little children for hours would get anyone in a bad mood after awhile. I've gotten my monthly breakout. I haven't gotten any cramps though !! That's the thing that's bugging me, I'll usually cramp really bad the week before and then not have a cramp for 2 days and then get one super bad one and then I get it. I thought I felt a cramp coming on last week but nope I think it was all in my head. And I feel like I have a cramp now but, I don't know if it's my feet, a legitimate cramp or both! Oh and for maybe 3 months in a row or more only my left ovary would hurt, and it would hurt before, during AND after periods. I have pretty short periods, lasting at most 5 days but are usually shorter. So that worries me too! It's the 18th today and I'm waiting on it to show up. As soon as it finally shows up I'm tracking it LOL. I don't want to be paranoid anymore. I know I shouldn't worry because I know when you do your mind with screw with you and you'll soon develop symptoms and such.. But someone please reure me that I'm normal LOL and that there's not possible way for me to be pregnant. Thanks again