Took nordette (ethinyl estradiol and levonorgestrel) as an ecp. When would I feel the side effects? I am gaining weight and lots of pimples.

No official data. Using nordette (ethinyl estradiol and levonorgestrel) as an ecp is "off-label", so there is no clinical data on side effects, etc. You don't say how long it has been since you took it; if only a few days, a little temporary acne and weight gain aren't that surprising. If it has been a month or more, you might be pregnant, and you should probably call your doctor.