Let me just say this first, pregnancy is always a possibility when you have sex, period. No birth control is 100% effective, so its even a possibility when you are taking it.
Let me give you two possibilities. First, the hormones in birth control can make your period go irregular. When you didnt take the pill in July, your hormones might have become confused, therefore making your period irregular. When it comes to your menstrual cycle, hormones are everything.
Now the second possibility, you could be pregnant. HPT's are not always accurate, for some women they never say positive through their whole pregnancy. The best time to wait to take a pregnancy test is 1-2 weeks after your missed period. You also have to make sure to use your first morning urine, it is the most accurate. Another thing you can do is go to your doctor and request a quantative blood test. This is the most accurate way of testing pregnancy. In this case it could go either way. Good luck!
