Went off pill a month ago, and kind of worried?

I was on the mini pill (Micronor) until about a month ago. During my time on the pill, I never had a period. I recently stopped taking the pill, and I still haven't gotten a period.

My concern is, at the end of February I had intercourse and the condom broke. I was taking my pills on time and never missed one, but of course I was still worried. I took two pregnancy tests mid April, and both were negative.

Is there any chance that I could be pregnant? My nipples are sore, and I know this could just be because I'm coming off the pill, but I also read that it's a common pregnancy symptom? Could someone ease my mind please...