I been cramping or in pain lower back for a day. the cramps feel like my period is coming and i already had it. it ended 2 weeks ago. what does this mean. i did have sex unprotected and my mate deposited semen in me. my tubes are tied though?

Abdominal cramps ?'s: After age 35, your ovaries produce higher levels of estrogen b/c of higher ovarian stimulation via the pituitary. The drop in estrogen just prior to ovulation is sufficient to simulate the onset of "period like" cramping. With tubal ligation, pregnancy is very unlikely, but in rare cases possible. If symptoms persist w/o onset of menses, obtain a serum HCG test to be certain.