Im on the pill, my partner uses condoms, took a test, it was negative. but still no period, is there still a chance im pregnant? why is it so late?

Complicated: If you take certain antibiotics on the pill they become less effective. Condoms can leak , have holes, and sometimes fall off. Do you see the condom after he ejaculates? Any stress, like work, bills, illness in family, your own illness, death in family/friends, weight gain or weight loss can delay or stop your period. Go to doc and get a blood test which is 20x more accurate.