avoiding pregnancy

Rebecca
So I recently had knee surgery which resulted in me getting blood clots in my lungs. I'm on blood thinners for 6 months can cannot get pregnant until at least after the new year. I have been on BCP for years but have been taken off them as of this week. because of the blood clots. 
I am also a newly wed!
We are currently planning to use condoms. 
My question is:  Should I use an ovulation test so I can avoid getting pregnant by not having sex on my most fertile days. Having been on BCP for over a decade I have no idea how to tell otherwise.