My husband & I are trying to conceive, I have my period the 3rd of every month. I calculated my ovulation date to be from the 13th to the 15th of last month February. It's now the 5th of March & I've not had my period & am nauseous on & off, crampy, back ache. I had a blood HCG test it was negative. But is there a chance I tested to soon? With the dates I gave when could I test & know for sure?

