My periods have been shorten from a normal 28 day cycle down to 25/26 consistently for the last 6 months or more. Last month I experienced a short light period (2 days light/2 days regular to light flow) when my normal is 5 days normal flow with the exception of the last day. I am 6 days late & have experienced mild on and off cramping for the last 2 weeks. A week prior to when my period was due it felt like I had ovulated for the 2nd time in the month. I have taken a few pregnancy tests but they are negative. Yesterday I started feeling light abdominal pressure. I am currently still breastfeeding my 17 month old (but mainly for his comfort), and since my period had returned when he was about 6 months I have gotten a period every month except this month. What could be going on?