In addition to what Glenda pointed out, sore breasts are also a regular symptom of being on your cycle. It doesn't always happen every cycle and can randomly happen to a woman who has never experienced it before. It has to do with hormone levels and such. Cramps could simply be because you are about to start.
I wouldn't be too worried if you used a condom properly each time (meaning it was never exposed to excessive heat of any sort, including body heat, before it was put on his penis and wasn't expired, didn't break) and your periods are irregular.
Try not to focus too much on what your body's doing and how it relates to pregnancy symptoms as most pregnancy symptoms are also menstrual cycle-related symptoms and we do become really overly aware when we're scared and get ourselves more worked up.
Okay thankyou heaps I am just worried
Hi avayah,iv never heard about sex making your period come late but it can be that you're worrying and stressing to much. I have had scares before and the more I worried the later it came. Sometimes I would get my period two weeks late because I was worried I might have been pregnant. Just tell yourself everything is fine and if you Dont start in about two weeks take another test.