How to interpret ovulation tests?

Hi ladies, quick question. We've decided to go for our first little miracle. I stopped using contraception 2 months ago. My cycle is consistent, 27-28 days. I've been doing some ovulation tests the past few days, but how should I interpret them? If the result is positive, does that mean I'm about to ovulate? Have I already ovulated, or has it already passed? I have absolutely no experience with this.

Thanks in advance!! ????