I've heard that digitals are less sensitive...Try another regular test in another day or two and then call your doctor for a blood test...I'm soo impatient however, I'd just call my doctor for a blood test asap =)
As Kels said...wait a couple of days and retest. If your beta was high enough to get a positive on one test, then after a couple of days it should be high enough to test accurately on a digital or just do another standard. Good luck!
I agree with Kels I would only wait a couple of days. Most pregnancy tests catch an hcg level of about 25 (give or take) where as digital tests detect at about 50. So since levels are supposed to double every 48-72 hours you should get an accurate result in a couple of days.
It could be that you are too early to get a true positive and sometimes the home tests detect different amount of HCG levels. I would wait about 2-3 days, not two weeks. Good luck and keep us updated!