I feel my uterus swelled nowadays, like an early pregnancy belly. But I am on my periods, so I couldn't be pregnant. I am observing this change form last 15 to 16 days. Also it feels pretty hard by pressing, and usually it can't b noticed while I lay down on my back. This time my period flow is also lower than my normal periods flow. But it seems nothing like pregnancy spotting. Also my last period came after a 40 day cycle whereas usually my cycles are of 32-34 days. Also, nowadays my pulse rate is usually between 85-104. I don't know what's happening. I am kind of worried please help.