Hi. Me and my partner had protected sex on the 18 th of November.. And I got my periods on 25th November. So I should be getting periods again by December end.. It is January 12th today and I still haven't got my periods. I'm really worried if I'm pregnant. I took a couple of HPT and it all came negative. Please tell me what I should do because my periods gave delayed for 18 days now and I'm very stressed. Am I pregnant?