You tested at 10 dpiui and got a BFP?!! THat is great - did you have any symptoms or just said the heck with it let me test - LOL I am 8 dpiui and not sure if the little bit of symptoms that I do have are early preg symptoms or from the progesterone that I am on. LOL
The other poster is right, but I wanted to let you know I tested at 10DPO/IUI with clear blue easy digital and got my bfp! I'm now almost 12 wks! But if it comes out negative that early for you, don't get down about it - it could just be you implanted late. Keep calm and good luck!!
Once you have ovulated, if the egg is fertilized it takes between 6-12 days to implant, and after implantation the egg begins to give off the HCG pregnancy hormone. Most pregnancy tests have a specific number of days they recommend waiting to test. I've seen 19 days the most. Either way, it is best to wait until you have missed your period or are late before testing, if you test early you may not get a fully accurate result, and you end up wasting money. I'd suggest waiting until at least the day of your missed period or a week later. If you test too early your HCG levels could be too low to pick up a positive result.