I went to my doctor yesterday and last time around ovulation I noticed my dogs were extremely clingy, and sniffing at my butt, and vag a lot (yes I find it weird and uncomfortable). So I asked him if they could sense that kind of thing. He told me that dogs are more effective than even the little ovulation tests. Most dogs sensitivity to human hormones are right on point, that's why dogs get really clingy after you've had Intercourse, are ovulating, or you're pregnant. Most dog become very protective as soon as their nose picks up the hcg or the LH.
Just thought this random fact should be shared. Some people are to weirded out to ask such things.