6th day of positive opk...

Has this happened to anyone else? I've been receiving very dark test lines since Thursday (darker than the control). The others before that were the same color as control. I know I should stop testing after first positive, but something told me to keep testing. I had one day of ewcm on Wednesday and we were able to Bd on Thursday morning. We also Bd the Friday and Sunday before it. Has this happened to anyone else? If so, did you get a BFP?