Help please!! Did anyone else try weeks estimator?

According to my LMP I'm between 4w6days and 5 weeks. I got my first positive pregnancy test 5 days before my missed period... Decided to try the weeks estimator test today and my result was 3+ weeks (since ovulation) which means 5+ weeks pregnant. Is anyone else coming up with this result or is my estimated due date wrong? Or....twins? Ahhh