Is it too late for a bfp??

Hi guys, I’ve been ttc with my husband. I only recently started using the clear blue ovulation strips. I’ve been on birth control since January and I know it can take time for my body to adjust. Since coming off the pill, I’ve had quite regular periods. This month my period is about eight days late. Every test I have done I get a BFN. I’m going to the doctors on Thursday for a blood test because I hate being stuck in this limbo feeling of not knowing! The day my period was supposed to arrive I just had a light brown spotting that continued for a week and now my cm is just clear and watery. I really don’t have any other symptoms.