Hello
I had the exact same thing around 6 weeks, a sharp pain, but it wasnt constant, it was on and off, i had no bleeding or discharge. Seeing as i am a total worrier, i phoned my out of hours doctor, who was quite a dramatic elderly man, and made a big deal out of having to go up and get an emergency scan because baby could be ectopic.
However, when i went up to get a scan, it did take a while to find bub, because s/he was so tiny, but they eventually found my wee peanut and everything was totally fine!
Im now 16 weeks, and I just had my 16 week midwife appointment yesterday, unfortunately im still getting the same sort of pains, but all over my tummy now, and the midwife thinks she will have to refer me to physio, although she said its nothing that will affect baby!
Hope all is good with you now, but if you ever are worrying a lot, could you even phone and speak to your doc? Everything is probably fine, but ive been told soo many times, its better for bub if you arent stressing!