I am in a long-distance relationship and did not have sex for the last two months. My partner and I are together again and have started having sex. On the first day, I had mild pain but no bleeding; on the second day of sex, I had mild bleeding. Today is the third day, and I had spotting after sex. I have also been on a mini pill (progesterone-only) for the last three years, and it has completely stopped my periods. Is the bleeding after sex normal, or should I be concerned?