Resting HR & TTC

Does anyone monitor their testing HR while TTC? I read that it’s similar to bbt? I have a Fitbit and I looked back on the past 2 months and in May it seems my HR increased by a few points around my time of ovulation and then decreased the day I got my period but in June it stayed pretty much the same the whole month. I wonder does this method have credibility? Does that mean I didn’t ovulate in June? I use OPKs and got a smiley both months but maybe that doesn’t actually mean an egg was released? Super curious about this! Not really able to bbt bc of a weird sleep schedule so it would be great to have another tool to monitor fertility. Thanks!