I don’t think that a lot of time had passed between the black and white flashbacks and the color “present”. At a minimum, enough time had passed for them to build the wall that they used to deflect the horde of walkers, so maybe 2-3 weeks? I like it better when they include something that says “3 weeks earlier...”.
We watched again last night, and Glenn mentioned that he had to get home to his wife three times. I wonder if Maggie is pregnant.
Watching it again, now to see if it makes any more sense to me.