Having symptoms, but negative?

Any input on this is great! I am 25 and a mother of a 5 year old. My fiance had a vasectomy 6 years ago with his previous wife. Over the past several months, I have been having symptoms of tender ,darkening of my areola, weight gain etc. I have my periods but they are very irregular now, and have ALWAYS been regular to the point i knew day and time I would start and how long it lasted. Now it comes and go, sometimes its spotty the whole time. Well I took a pregnancy test 2 months ago (NEGATIVE) Over the past couple of weeks I have been swollen and puffy, to the point where my fiance notices. But on top of all of this, I have had movement and hardness to my stomach.. I catch myself daily completely stopping what I'm doing to put my hand on my stomach because I feel it. At first I thought it was gas, but now I'm questioning that because I will feel it, and put my hand to where I felt and its hard in that spot. I made an appointment for this past Monday to go to the doctor but I chickened out, because I don't want to look like a idiot because like I said my fiance had a vasectomy and I have had my periods. I have heard of people having periods during pregnancy, and I have heard of women getting pregnant after a vasectomy. But what are the odds of it happening together??? Any advice or comments please.