Hi, I have always been irregular, sometimes I miss my period for two to three months. However, for the past two months ( May and June) I had been pretty regular. I began having sex for the first time (mid June), but always used a condom, and haven't had my period since. I was supposed to get it on July 1 and it is now July 23. I took a test on July 4, July 9, and July 21 and all three have been negative. However on July 21 I saw some mild spotting and have been feeling a bit nauseous since. I also began taking the pill on this day. Are there any chances I could be pregnant?