The aimstrip can detect HCG levels as low as 20. HCG levels will get into the 100s of thousands as the pregnancy moves on to give you an idea how sensitive a test is that picks up 20. That would be as little as six days past ovulation if the egg was fertilized. That's about the best out there. I would still test again in a few more days. Use a first morning urine sample so it has had more time to "stew" and pick up the HCG.