Hi i last had a period on the 18th feb and since then i have com of bc i was due for my period last week but nothing came and still nothing now last week i was feeling tired had spots around my nipples and needing to wee mre than usual and getting cramps. But this week i feel fine with the ocassional cramps i have took 5 tests and all negative the last time i tested was today. Is it likely that i could be pregnant?