how soon after implantation until I can use a hpt?

[nshapland]

How soon after implantation cramping should I use an hpt?  It's so dumb of me to get my hopes up--but I had cramping at day 6-7, a week before my period is due, so I am hoping it was implantation cramping.  How early can they tell at the drs office (I didn't take meds this month so there wouldn't be a false positive from hcg)?  
The waiting is driving me crazy.
Thanks

[llayton2010]

I took one on day 6, 7, 8, 9 after transfer (IVF) all were negative. I used First Response and EPT.  I am all out of HPT, which is a good thing.  I think I should wait until my blood test.  Let me know if you find out which ones are the best.  Thanks and good luck to you!

[nshapland]

I'm not sure which one is best. I'll do a little research...

[nshapland]

Alot of people on this board take tests at day 10 or 11--I know a false negative is a possibility, but it can show up that early, right?  
What about at a dr office? Can a blood test detect even a very low amt of hcg in the blood?

[llayton2010]

Have you heard which HPT is the best for early detection?

[Clysta]

You want to take a test when you're period is due or late. Any sooner and you have a higher chance of false negatives or a wrong reading. Even people who test when their period is due don't always show till later on.