I am on the contraceptive pill and have been for a few years now. My period usually comes on the same day and for the same length of time. Last month, I missed the first pill of the packet and had sex 4 days before my period was due (no condom), but my period ended up coming 2 days late and was much lighter than normal. I was pretty stressed on the days leading up to it, thinking I may be pregnant. This month, my period came 2 days late again and was heavy on the first day, and is now becoming weaker much quicker than normal. I am really starting to stress now because my periods have always been so regular and timed, and now they have suddenly changed. Could I be pregnant?