Positive OPKs, high vs peak in premom

I just started using OPKs for the first time this month. Today I got my first positive. I'm using the premom app and it shows as high, but not peak. What's the difference? Glow registered it as the darkest line. I attached my progression as well as a picture of todays test. I'm asking cause my husband and I BD tonight, but I dont know if we will be able to tomorrow and Thursday because we work and then I teach class in the evenings. I thought a positive meant I was most likely to ovulate tomorrow, but then when it didn't say "peak" I wasn't sure.