Is it normal to have such a short period after birth control?

I stopped taking birth control pills in June. I had one normal period. My next cycle was 35 days - 6 day period. This past cycle was 43 days! But my period lasted 2 and a half days...is that normal? My husband and I are trying to conceive. I thought I was pregnant, took a blood test and the next morning I got my period (very short period). Could it be that I ovulated much later in my cycle and that my "period" was implantation?