Loestrin is one of the pills that has been known to give women shorter, lighter periods, which is a main reason why women choose that pill (or its generic equivalent in the form of Junel). It's what's supposed to happen. There's nothing wrong. Having such a light period, I would think, is a blessing. If you weren't on that pill, you'd probably not be happy having 5-7-9 day periods with painful cramps.