No sore breasts

I am 15 wks 5 days pregnant and my breasts haven't grown at all during my pregnancy not have they ever been sore. Since my nausea has gone away I no longer have anything to remind me I am pregnant. I definitely don't look pregnant so I am just waiting until next Thursday for my next scan. I am nervous something has happened to my baby because of my lack of feeling pregnant. Is this normal? Has anyone else ever felt too normal? It's my first baby and I have had one miscarriage so I guess I am just freaking out.