Thinking too much

Sandra

I'm 37 and hubby is 51. We have 4 children trying for #5. Had nexpalon removed 11/14. Had a cycle on 11/24. Nothing in December, BFN. Cycle started 1/1. Checked CM on 1/5 had raw egg, but negative opk..did the did that night and morning. Since then I've just been crampy....could it be fertilization and implantation I'm feeling??