Has this happened to anyone?

I used to get very positive ovulation tests like clear as day which would last 2 days long. I used to ovulate anywhere from CD 18 to 21 and my cycles would be around 35 days give or take. For the past 2 or 3 months i havent been getting positive opks so im like...shit...am i not ovulating now? I tested past CD21 and nothing. Last month i didnt get a positive opk and i had NO fertile cervical mucus until about 4 days before my period. Im talkin like watery EWCM. I thought it was weird and my body was confused and left it at that and got my period 4 days later. This month the same thing happened! No positive opk until CD 23 so i left it and stopped testing. Im supposed to get my period tomorrow and started getting very watery CM like 4 or 5 days ago. 3 days ago i took an OPK and it was DARK. Super positive. Ive been cramping for like 10 days already because im gonna get my period any minute now. Why would i get a positive opk 3 days before im supposed to get my period? It was like CD 33. Im worried that if egg met sperm then God forbid im just gonna bleed it out with my period or something!

What im trying to ask is:

Has this happened to anyone?

Did you or someone you know actually get pregnant like this? Actually conceive a few days before your expected period?