Can you ovulate on depo?

Kailey • I am 19 and currently go to college to be a zoo vet. I am currently happy with the love of my life and am getting married next summer. I believe in Jesus Christ our saviour!
Last night I had a creamy discharge that was extremely stretchy....I was told this means fertile and or ovulation. My fiance thinks its just his cum from the night before coming out because it has no where to go. It had no smell. What does it really mean? If it's fertile how can that be because my shot is supposed to keep my eggs in my ovarys.