Starting to lose hope..

I took ovulation test and I had a peak on Friday .. we BD Friday And Saturday.. Which I thought we be enough because we both are very busy people .. I had cramps on Sunday.. so I’m pretty sure that’s when I ovulated.. and I’m now 13 dpo and I took a pregnancy test .. it was a FAT negative.. and my AF is due. My younger sister got pregnant with her one night stand and she didn’t even try .. and my friends are all pregnant.. I just feel like it’s not use.. i started have bad cramps this morning .. like period cramps and I feel like she’s about to come .. any tips or advice..?