Dark Stranger

I suppose this could all just be me being paranoid, but I'm pretty sure my period should have arrived two days ago (it came around September 3-6 last month). On the other hand, there's a possibility it could be shifting on me (which it did back in March - it came six days early), but I digress. I was also having some mild aching pain in the sides of my pelvis, which radiated to my hips and into my thighs; it feels more like numbness rather than pain. The aching is something I've felt before, but I don't know if it's merely a muscle ache or it has to do with my ovaries.

I guess I'm just paranoid about pregnancy, even though I would say the chances are rather low - I had protected sex twice over a period of a couple days about two weeks ago, there was no ejaculation involved, and the condoms were still intact (no holes, no coming off, etc.) This occurred during what I believe may have been my fertile time - exactly two weeks after the first day of my period would have been September 18, and I had sex the 18th and the 20th.

I also want to ask this: Is it possible that I simply didn't ovulate this month? I realize at my age (19) my body is getting ready for childbirth, whether or not I like it, and this can cause changes in my cycle. I also know that women who do not ovulate usually do not have a period. If this is the case, is it normal for this to just be a one-time thing? Can a lack of ovulation one month mean it will continue, or is it more likely I'll get my cycle as normal? Despite moderate irregularity in my cycles since they began, I almost always have signs of ovulation, which consists only of soreness in my breasts and nipples. These didn't come this month, which is leading me slightly further into the belief that I may have missed ovulating this month.

Does anyone think I should be concerned? If my period doesn't come soon, I'm considering dropping by the local health store and picking up some black cohosh...which, from what I know, has been used for inducing one's period. I just find it odd that when I had a condom mishap, it occurred during my fertile time and I never got pregnant, so I'm not quite sure how pregnancy could have occurred when my protection worked as it should.