IUI Attempt

I am 31 and my hubby 34 years. We already have a son who is 3 years old. We conceived him on our vey first try naturally. So when we tried for #2 it came as a shock that we could not after TTCing for more than a year. So we went to RE and all tests came back positive and fine. Nothing was wrong. Ao doc suggested IUI and so we opted it. Now i am only 3 DPO and I am already impatient. Am i or am i not pregnant?! I don't know how long I can wait before I test. It's just making me crazy.