Am i or not? I could use some help please.

I have irregular periods, i take birth control but im not always good at keeping up my pills, i stoped on the pills for some time, now im just starting them back up full time. I had sex while on my pills and made sure to take my pills even after having sex. It is now the third week going on the fourth week since i have had sex. He did ejaculate in me. Two different times. Main things i am having problems with is tender breasts mainly around the outside of my breasts. Around my nipples do no hurt at all. The pain is worse some days, and then not so bad the next. The pain in my breasts started around two days after i had sex. Another problem is constipation, BAD! So bad i can have weird gut wrenching feelings inside my stomach. But it didnt really start until around the time late of the second week. My last period was around the 10th of June and they usually last around 4 days. I took one bc pill early morning before i had sex around 3am or so, that same morning i had sex, the next pill i took was around 4pm that same day (i get freaked after sex), the next day i took two bc pills at the same time around 4pm also, and i continued with one pill a day after that up until the wednesday of the second week. I had stoped the pills because of the symptoms i was having, and was afraid that if i was pregnant then i didnt want to hurt the baby. Also that maybe the hormones in the pill were causing my breasts to ache because the kind im on is a new kind to my body, and they dont really sit well with me. I thought maybe since i stoped my pills that i would leave room for my period to come by now, its been almost a week and a half since i stoped the pills. I've been really stressed out these days thinking i've been pregnant (im a very paranoid person), plus i lost my job due to going on vacation with my family starting tomorrow. My skin broke out as usual when i have my periods and i've had the constipation associated with periods, but no period yet. Can stress cause the period to not come? Or maybe i messed it up with my pills...i have no idea because im irregular and i was going by the time i had my last period. Im a little iffy on the whole being pregnant thing, i really havnt had much to go on, and i'm trying to wait till next week for a pregnancy test. I want it to be accurate and around 4 weeks after is accurate right? By then i should be able to know right? I will do three tests. But should i be worried? Do you think?