Help a mama out

My af is very regular. It’s almost always on time maybe within a day or 2.. my sons dad and I have decided to part ways as of February. Back story we were together 6 years and engaged he cheated on me after my son was born and I finally caught on to it so I left. Hardest thing to do ever. But anyway yes we still were having sex yes I know bad me but he is the only one there and I didn’t want to open up to people. Now we only have sex like 1 time a month. This month it was the 14th my fertility window was the 17th and that week my af should have been here the 5th and it’s not here.. kinda freaking out.. I have cramps like I’m going to get af but she isn’t here. The longest it has even been late was 3 days so I’m stressing out.. I am really hoping she shows up... I know most people wouldn’t want her but I do. Please give me some advice and idk just something to keep my mind off of this.. pic of my handsome son who will soon be 2