Confused

Just a little confused my husband and i r trying to conceive our 2nd child we've been tryin a couple months now with our first it took a month i have been somewhat stressed i got my last period may 3rd and i usually get it same time every month and still nothing yet just a little confused any ideas of y i havent got it yet ive taking 3 tests and they all came back negative i dont know if its too soon to tell or what