My periods are usually 5 days long and regular as clockwork. I don't get PMS, just some mild-moderate cramping on the first day of my period. For the past couple of months, I've felt like I'm on a constant period, without the period! I have that heavy, achy, bloated feeling and I've even been to the toilet a few times to make sure I'm not still on my period! I've been checked for STIs/STDs so I know that's not the problem. Any ideas?