Conceiving

I have a serious question ppl... My last period was in August then nothing for 2 1/2 months. During those months of no period me and the hubby had sex jus about every other day. I had tender breast, very sore nipples, nausea, and loss of appetite also. A couple of weeks ago I started sporting it was very light and lasted for about 2 days. Still no period. This past Tuesday I woke up with spotting that was a brownish color then thru out the day the blood got redder and heavy. So I assumed my period came and it's still here but I have bad back pains, I am constantly dizzy and keep getting nauseated a lot. What's scaring me is that I called my gyno for an appt to see what's going on with me and my irregular periods and the nurse called me back and said to come in on Monday because I could possibly be pregnant and don't know it but still having a period. I was so stunned that I didn't ask questions. But what I want to know is, is that possible to be pregnant while having your period. I've heard a lot of ppl say it's possible but I don't know what to believe... Your thoughts please!!