Baffled by negative tests

This is my current bbt chart, in previous months I had always gotten a vvfl on dollar store tests by 10 dpo. Yesterday i saw a whisper of a line but couldn’t tell if there was any colour. This morning it’s stark white...I’ve been feeling breast soreness, on and off cramping and sharp twinges... and with my lovely temps I’m quite surprised it’s negative. 😞😞 I’m a bit frustrated and disappointed. I’ve had 3 miscarriages, an ectopic in Jan and a chemical last month