When to test?

I had a chemical pregnancy last month, but we started trying again as soon as I stopped bleeding. I do OPKs but I have never gotten a peak fertility day, only highs. I started this cycle on the 12th, and have had highs every day in the opk. When can I start HPtesting? I feeling a lot of the same symptoms again that I felt last month, but with an additional two or three days of very light cramping. I didn’t have that last month and I’m praying that’s a good sign.