Me and my partner were treated for chlamidya. I had symptoms from the immediate onset until I took the treatment when they went away. 10 months later they came back following a sudden discharge of blood. Could the chlamidya have lain dormant, either in me, or my girlfriend , for 10 months ,with no symptoms?

Did you both take the treatment for the entire prescribed amount of time? If not, it came back.

Otherwise, you had been re-infected by your partner.