Early Pregnancy & getting more exhausted!!

Any early pregnancy mommas out there who are getting more and more tired with each day!? I am currently only 6 weeks & 1 day. I've been worrying a lot because it is my first pregnancy and I'm scared of a miscarriage.. Anyway I was an active person before pregnancy ( gym 5x a week) and now my doctor said still be active, but literally everyday it's been getting more and more difficult for me!!!
Anyone experience this? I haven't had any symptoms other then sore breasts (like can't even touch them they hurt) & cramping which I went to doctor for and they said everything looks good.