Birth control, delayed periods, and the possibility of pregnancy?

[fourwinds]

Okay, forgive me if this gets lengthy.
I have been on a small dose of Yaz since October. It was given to me to regulate my very irregular (and often absent) periods. At the end of May (on the 18th), I had surgery on my stomach and stopped taking the Yaz. I had been forgetting to take them all month, and had a very light period right before the surgery. Anyway, come June, I got my period in the middle of the month, like on the 14th, which was weird considering my periods usually come at the end of the month. Then, on the 24th, I lost my virginity. We used a condom and were careful, etc. Since then, my boyfriend and I have been having sex once a week, using a condom each time.
Anyway, it is now the 17th and I've yet to get my period. I had some of my regular symptoms of an oncoming period (craving sweets, cramps, etc.), but no period. Keep in mind, I haven't been taking the Yaz since May. Also, something to note, I have poly cystic ovarian syndrome. I don't know if that contributes to the issue or not. Also, I think I may have ovulated sometime after the 24th. I'm not entirely sure though.
Can anyone tell me what's going on? ): I'm very worried.

P.S. I took a pregnancy test last night and it came out negative, but I'm not entirely sure about it because it was a really cheap test, so I'm still worrying. I might get another test today.

[JoyRenee]

fourwinds- that happens so often! The stress of wondering if you're pregnant can cause pregnancy symptoms and once you take that test and know... BAM! You get your period.

In regards to why you were late- the surgery could have set your body off schedule. The PCOS can also affect your periods/cycles (longer cycles, for example). Without the YAZ to regulate you, you may not have regular periods because of the PCOS.

[fourwinds]

update!
i went and got another pregnancy test.
when i went to take it, i started my period.

(:
my theory is that god is making fun of me for being such a worry wart.

[curious90]

i would for sure get another test. and your period may be going back to the end of the month. i'm no doctor so i have no idea about how your PCO effects anything. but i've had those scares before too, and i would suggest buying a test with a better reputation and get a box with more than one incase you ever need any more. and i know this may be a myth but take the test first thing in the morning with your first urination of the day.