Temps with successful cycles?

When I was TTC for #1 I noticed after ovulation my temps rose in the 98 degree variation even if they weren’t successful. It’s been about 2 years and now I’m trying for #2 and I’ve noticed my temps don’t go up that high anymore after O day but I haven’t gotten a positive either. Is this something that could have changed since it’s been a while? Has anyone gotten a positive with temps below 98?