What Causes Scant Menstrual Bleeding With Abdominal Cramps?

Hello, im writing because im a little but confused as to whats happening lately. About 4 days ago I thought my period was starting because there was a small amount of what looked like peach/pinkish blood on a pantylinerI put a tampon in and even had cramps but when Iwent to change it nothing was there at all! My periods typically l ast about 5 days and tend to get heavy between day 2 and 3 and this bleeding came around the time it usually does each month so its makin me a little concerned. Can I be pregnant?, have cysts interferring or something wronf? Im 32 yrs old and am not on bc since my husband wants to have kids.. please help if u can thanks so much