Help with OPKs!!

I just had a provera induced cycle and then started using OPKs on the last day of my period. I just took the bottom test tonight and noticed a drastic difference between the past three tests and the test tonight. Did I ovulate already? This is my first cycle since coming off BC seven months ago, so I have no prior information to go off of!

Any help is appreciated! I am totally new to OPKs, so I feel a little lost.