When did you get your bfp

Lena
Friday will be one week late for me and I've tested twice now and gotten bfn. Oth times. My doctor wants to start me on progesterone but I'm afraid if I am pregnant it will just cause me to have a miscarriage. I had a blood pregnancy test done 3 weeks ago and it came back bfn but my so and I have had unprotected sex a few times since then. Have any of you ladies tested and gotten bfn but waited a week or too and then gotten bfp?