Question about pregnancy and Vasectomy

So my husband had a vasectomy last June so almost a year ago. I am currently breastfeeding and obviously we are having unsafe sex. Lately I have been feeling really crampy and my boobs are so sore (I have 3 kids) so I am kind of familiar with pregnancy symptoms but I feel like there has to be no way.. has anyone gotten pregnant with their husband having a vasectomy? Also this could be me getting my period soon too. I hate that the symptoms are so similar.