Mentally exhausted...Bfn and no Af

It's been 41 days since the start of my last period and I've never been this late. I've taken multiple pregnancy tests and all negative! I have no idea what's going on and I just want to know already. I've been having pregnancy symptoms and PMS symptoms...but nothing! Please any advice will help me. If anyone has gone through this please tell me your story. I need some peace of mind. Tia.