HELP!

Madison
So I have missed AF for the 2nd time & I've been having some slight symptoms but not many like I haven't had the morning sickness or anything obvious like that. We have been taking test & they all are a BFN we had one that we thought was a BFP but come to find out that test had been sitting out for a while so it was not correct. We are still currently testing & hoping for a BFP but nothing yet. I just don't understand how I miss 2 AF & still not BFP.