My period for a year now has been pretty regular coming 26-31 days we have been trying to conceive for 4 months, negative after negative, well in February I got my period the 14, we DTD on cycle day 11, 14, 15, 16 and 20, I was expecting my period on March 15 or 16 and nothing! I have taken test after test and negative but it's now cycle day 35 and no period still. I feel like I'm going to get it but I don't. I'm getting worried! Any thoughts?