Why is this happening??

My period is 5 days late and I keep getting BFNs. I'm wondering if I ovulated later than I thought? I had EWCM for a full week so I'm not sure exactly when in that whole week I ovulated. Either way that would have been from 8/9 to 8/16. I should be getting accurate results now right? I still am getting symptoms and something just tells me I am pregnant. But idk with these BFNs 😞😕😰 could it be because I've only used the .88 cent tests? Once I go shopping I might get a FRER but I don't want to waste the money if you guys think I might just be out this month. Do I just face it and accept that I'm not pregnant? Or keep testing until AF shows, maybe order blood work from the doctor?? Anyone else going through this?? Please help.