3 days late---confused!

I'm three days later and we are TTC. I have been off BC for about 3 months and was regular the first month. We did the BD when I was fertile....first time trying using glow app. I am in Vegas for a work convention and my mom is with me so I don't want to take a test with her (I would like her to be surprised...when we tell them and for my husband to know first). My confusion is I have no other symptom besides a missed period to feel pregnant. I said to my husband last week that I feel like my boobs are huge lately but that is it. They do not hurt, I'm not tired, do not have food aversions or overly hungry. And I do feel like I could get my period but I'm never late??  Not sure! Anyone else not experience any side effects and be pregnant? How soon until you took a test?