I'm on Loestrin 21, so it's normal length. But I'm still getting a shorter period.

I can tell you that studies say that if you are on Loestrin 24 you will most certainly get a shorter period, but it will take a couple months (up to six for the full effect). Because you are taking hormone pills for 24 days and only on the placebo for 4 days, you should adjust to get your period for about 4 days or less. Check the loestrin website or the FDA website for specific information.

on the pill for 2yrs get no priod nothing no spotting either