just removed IUD

In June I had my IUD removed, a week later I had a peroid. It has been so long since I have had a peroid I don't know my cycle length and duration of a normal peroid. my husband and I want to conceive again and I was hoping to start right away in trying. I calculated my ovulation based on my first day of that "peroid" and just a kind of normal length and duration. (28 days and 14 to ovulation) we tried for a longer window than just that in hopes that we catch it. my question is when can I test? should I wait for when my "next peroid" should be? After having an IUD removed an irregular peroid is to be expected, plus I always had an irregular peroid before my first child. I have been feeling nausea and cramping with no sign of bleeding, and my breasts were a little sore today. Can I test now or wait for next week?