Lately it's been 6-7 days a week for at least 30 minutes. Doesn't matter what kind as long as it gets my heart rate up (walking, running, dancing, aerobics, etc.) I may incorporate weights at some point, but for now it's push-ups.
I don't count the days I workout in every week anymore, I just make sure that working out is always on my list of things to do for the day. Obviously, there will be days where I won't exercise but I just make sure staying active is always apart of my lifestyle.