Best time to have sex when you have a positive ovulation test?

I've just had my first positive ovulation test postpartum. My daughter is 10 months and I haven't had a period yet. When is the best time to have sex to get pregnant with a positive opk? The test line is darker then the control line so I'm hoping that is better then it just being the same colour! We did have sex last night already because yesterday the lines were darker hen normal but not as dark as the control line