Ovulation worries!!

Me and My SO have been TTC since October 2014 (which is when I came off the depo injection) my periods became regular (same time every month) in July/August. Every month when glow is saying I am ovulating I do a ovulation test but they always seem to be negative! I even do one either way of the ovulation period but no luck in any ovulating! Do you think it's worth taking a trip to my GP?