Could I be pregnant 8 months after having baby #1?

I had my daughter 8 months ago, in December. Because I had her via c-section, I waited a LONG time before having with my hubby again - as in 5 months long. Since then, we have only had a total of 3 times (I know, poor him, but I just haven't been in the mood since I'm always so tired after taking care of the baby, working, school, etc.,but this is besides the point), and each time we used contraception in the form of condoms and spermicidal lubricant. I never had a regular period before my childbirth, but since my menstruation cycle started back up again, I seemed to get my period every 28-32 days. The month of July, however, I did not get my period. It is now August, and I haven't had my period since June 17th. Is it possible that I could be pregnant? I guess I am asking this on here because I'm wondering if it's possible to get pregnant despite only having had 3 times and using contraception (properly) all 3 times. I have heard that women are more fertile after giving birth; is this true, and for how long does this last? (I didn't have again until 5 months after giving birth.) Also, I'm wondering if it's possible to have a normal menstruation cycle (semi-normal, anyways) right after giving birth and then slip back into an irregular cycle? I'm sorry for all the questions! If anyone could help me out, it would be much appreciated! Thanks in advance. :)