No period & breastfeeding

Since having my daughter 17m ago my periods have been really intermittent. So much so I can do 3/4 months without a period and then have one like a normal. My husband and I are trying to have a baby, I haven't had a period now for almost 3m again. I am experiencing something that resembles my morning sickness, slight knot in my tummy. But they I also felt as though I was coming on my period the other day. I am having some white discharge that I used to get at early stages of pregnancy. But I still feel in my heart that I am not pregnant & don't want to take the test because I don't want it to conclude negative. Do you think my mind & body are playing tricks on me because I want it so bad? Any advice on breastfeeding and becoming pregnant?? Thanks in advance lovelies xx