I'm pretty much dealing with the same issues but I've been having irregular/abnormal periods the past 2 cycles. My last normal one,at least what's normal for me was end of March. Last 2 periods came late, was MUCH lighter, and light-brown instead of shades of red. The last one in June was only about 6 hours and actually I think it was spotting rather than period so really makes me think something is not right.
Right now I'm 2 weeks late. I was supposed to start the 4th/5th(I use apps and some say 4th, some say 5th).
But yeah my nipples the past 2 months have been sensitive on & off. And my partner keeps asking me when he goes to touch them why they are "hard" and I really never know what to say. They will be hard when not cold or aroused and stay that way.
I wish I could give you an answer but I don't know what's up with me either.
I thought maybe pregnancy but haven't gotten around to testing as I really don't feel pregnant but some told me it's possible. Going to the doctor thursday so I figured although I'm late now, really no point in testing if I can get it done for free at the doctors right? Plus they can do a blood test that's more reliable.
I also said if it's not pregnancy at least being at the doctor's already they can run further tests to see if maybe it's something else hormonal.
I know regular hormonal imbalances from what I've been told and researched, can resemble pms symptoms and pregnancy symptoms. They can delay your periods.