Pregnant before marriage

Was Anyone else planning a wedding and had a pleasant pregnancy surprise? We decided to elope in a few weeks and have the wedding next year after the baby is born. I don't see anything wrong with this and we are thrilled to be having a baby in November! However, his sister has made several rude comments and on Easter mentioned she doesn't think anyone would come to our wedding next year "since we are already married." I still want a chance to have my wedding and wear the dress I bought. Does anyone see anything wrong with this?