Pregnant while Nursing

My husband and I are TTC Baby #3, I am still nursing our 10 month old daughter and the last day or so I have become extremely 'engorged' feeling. This morning I was so engorged I had to wake her up to relieve myself! I have not had the engorged sensation since she was months old. Could this be HCG hormone making me engorge? Or feeding patterns have not changed. I am on cycle day 20 and should be about 13 DPO.... I think it's too early to test. But I have been experiencing cramping and headaches through the last few days....