Oh, I have this "condition" or something similar, too. Not even with close friends but with strangers I pass in the supermarket. It doesn't happen often but it's very significant.
I think I somewhere read, but unrelated to ovulating, that this was made by nature to find suitable partners. Probably that natural smell is intensified by ovulating.
edit: And to be honest: I never told anyone before that I sometimes sense this different smell and I'm not sure I should. Women could probably feel uncomfortable and think their smell is somehow "bad" when others can sense it. Not sure.
You’re likely perceiving female pheromones. There have been studies that men can reliably detect fertile phases from sniffing worn shirts alone. I‘ve tried diving a bit into this topic after noticing something fruity (a good smell) in the middle of my cycle, which somehow intensified when being around my so. Interestingly it disappeared in the years I’ve been on hormonal contraception (stopped now due to a couple of more severe side effects, luckily I haven’t been on them for long).
Asking the women whether your perception is true would likely have led nowhere as most women are not aware of their fertile phases.
Search keyword seems to be ‚copulins‘, but the area appears a bit underexplored. Lots of companies trying to sell snake oil. Lots of urban legends about mind control. Some girls do try using their natural perfume to their advantage though.
The thing about compatibility you mention is more related to the immune system I think, and mutual.
I have a tendency to associate with alternative types who are aware of their cycle and are happy to talk about it, and have confirmed my observation by asking on multiple occasions.
I think I somewhere read, but unrelated to ovulating, that this was made by nature to find suitable partners. Probably that natural smell is intensified by ovulating.
edit: And to be honest: I never told anyone before that I sometimes sense this different smell and I'm not sure I should. Women could probably feel uncomfortable and think their smell is somehow "bad" when others can sense it. Not sure.