Trying so hard!

My husband and I have been trying for the past two months to get pregnant. We have a two year old little boy right now, which I feel was so easy to become pregnant with him. 
My cycle averages about 31 days, and my tracker says I'm coming up on my fertile window here in the next two days. We have been trying ever since my period ended ( we are both determined)
I've considered buying Ovulation test strips.. Has anyone had luck with these to determine when they are ovulating?