Period while Pregnant

I have read many post here that lead me to believe many women think if they have a period they are not pregnant. Twenty years ago, I was having sex with my boyfriend on a regular basis. I was using condoms, but condoms fail so therefor, I felt if I got my period and it was normal, I wasnt pregnant. Three months after my first encounter with sex, I had noticed weight gain, so I started exercising more, and felt it was because I was no longer playing soft-ball since the summer was over. The exercise seemed to do nothing, the scales kept creeping up regardless of what I did to lose weight. I was having my period regulary, so pregnancy never entered my mind, until I was sitting at the xmas dinner table and I felt this strange flutter. I thought to myself...it must be gas...but then again it happened. I made an appt. with my gyno and sure enough...I was pregnant. Strangely enough, when I laid down on the exam table..my stomach became a nice round knot. I knew before the test came back and so did the doctor. I was shocked, I had every period on time, with normal flow. The doctor told me that its not as unusual as I thought it to be. For the next 3 months (7months pregnant) I continued to have regular periods. At the eight month, I spotted and never showed any signs of a period after that. I gave birth to a beautiful baby girl. Oddly enough, on the day I should have started my period. Today she is a beautiful 20 year old.
My point in posting this is...pls dont believe that just because you have a normal period you are not pregnant. It does happen. More often than you think.