I know exactly how you feel - and really echo what everyone else says. You'll be fine - the fact you're getting aches and twinges is a really good sign. It means everything is stretching (which means baby is still growing!!). Honestly the amount of times i asked my doc or midwife if these pains where normal, and all said absolutely yes..
I'd had a m/c last year, and it definitely impacted on how nervous i was this time round. Those first 3 months were really quite miserable simply because i was so worried. But you're past the earliest dangers now (most m/c are before the 10 week mark) so all in all it sounds like you're having a text book pregnancy!
Just try to relax, and i promise once you've had your scan you'll start to believe it's all going well. I know i cried at my scan because of the sheer relief!!
So chin up, and allow yourself to start enjoying the fact you're going to become a mum!