Hi there, I'm 18 years old. I'm currently on my second month of a tri-phasic birth control called Tri-Sprintec. The first month I started my withdrawl bleed by spotting lightly on the second day of placebo pills and beginning a regular heavy period the third day. This month I am into the 4th inactive day and have not yet had any spotting or signs my period is on its way. This concerns me because ever since my last period, I've had some other problems like stomach bloating and an uncomfortable pressure in my abdomen (may be caused by gas and I'm on probiotics to try an resolve that issue). I've also had to pee much more frequently, as if what I'm drinking goes straight through me or my bladder is under pressure. I've been very fatigued as well. Keep in mind that me and my boyfriend have never had sex without a condom. But the first week on the pill last month, I took plan B right after sex one night because we thought semen may have leaked over the bottom of the condom. But again, I had a period after that and I am fairly faithful in my pill taking. Only being a little over an hour late one night or two. What is the probability that I'm pregnant? Me and my boyfriend had sex yesterday on my third placebo day. We did use a condom. But I know that condoms can fail without visible evidence correct? Any input is welcome. Thank you!