I'm scared to death here, and a truthful answer would be greatly appreciated. Thank you.

My boyfriend and I were recently together and decided to fool around a bit. Mind you, the two of us are both virgins and neither of us had our clothes off at the same time.. however, we did do quite a bit of experimentation with oral and manual stimulation in addition to mutual masturbation.. and these events occurred multiple nights over the course of last week. At one point, I am certain that he ejaculated in his pants while I was in his lap, and I'm wondering whether or not the fluid could have seeped through both of our pants, since I am aware that contact between fluids can indeed exchange sperm, thus giving a chance for pregnancy. Recently I've been experiencing troubling pains and such that are beginning to make me doubt my safety in the scenario. I've exhibited the following: breast pains, headaches, fatigue, stomach pain, and a small amount of nausea. I've even started to feel that my areolas are darkening or getting bigger, but my hypochondria might be in-play with that. However, I am within a week or so of my period, and a lot of these symptoms are relatively normal for me to have during PMS. I really cannot tell whether I'm psyching myself out and causing more anxiety than is warranted, or whether I should legitimately be concerned. I feel sickened with myself and terrified at the prospect of pregnancy. Moreover, is it possible that I could be pregnant? Is my anxiety causing me to experience more symptoms than I really have?