So I've been having cramps in the top part of my uterus it feels tight or full but crampy. This has been happening for the past five nights, but only at night when I go to bed....I'm really confused, I usually get cramps in the morning right before I start my period if I cramp that period, but no sign of at not even spotting and I'm irregular so I have no clue when or if I'm late. Any ideas? Also my nipples have been sensitive for a few days but that's it.