Hello ladies. I have just found my way back to the bump boards (mainly tttc) after many years away...I HOPE this is the board I will end up on soon

As a quick intro, I am 36 and my partner is 40. We have been ttc for the past 3 years, however I did not temp or use OPKs or anything...we have an appt with a fertility specialist in November to possibly begin IVF...
My question is if anyone here has had experience with a very, very late BFP (on home urine tests)? Reason being, I am currently 17 days late (based on my average cycle length of 26 days)...so I am on day 44 of this cycle. I have NEVER had a cycle longer than 30 days. Over the past couple weeks I have taken 4 or 5 pg tests, all negative. I don't want to get my (or partners) hopes up that I am pg because I know that woman can have a random missed period cycle. However, I have also heard of some cases of woman not having enough hcg in their urine to detect, but maybe I'm grasping at straws. Just wondering if anyone experienced this and the outcome. Thanks and hopefully I will be a regular in the near future...
Re: Question about VERY late bfp's