I'm not sure if I'm pregnant... as I've never been oregnant before. Here's the thing...

My last period was from 30th Sep - 7th Oct. I had unprotected sex between 23rd - 26th Oct. Since then I've had stomach cramps and jabbing pains in my stomach... particularly lower stomach. Sometimes feels like my period has started, but when I check it hasn't. Have been experiencing lower back pain.. wind (nice eh??) constipation (even nicer!!)... I'm sure I should have started my next period by now. I've taken two HPTs but both were negative. Could I be pregnant?

Thing is... I would be really happy if I was... but worried that if I am, and I don't know, I may do something to harm the baby. Also ... I've read on here that some people don't show up for quite some time as positive on a HPT ... just worried as people will expect me to carry on as normal... carrying heavy things/moving things, especially at work.

I was at the doctors earlier today for another reason and mentioned that it's possible I could be pregnant and said I'd done 2 HPTs that were negative... but they never offered to do a test for me and never gave me any advice. Any ideas?