Ok my girlfiend is have a light redish pink discharge,? is it?!

Ok my girlfiend is have a light redish pink discharge,? is it?

ok she is on birth control and the last 3 periods have been getting lighter and lighter and they get shorter and shorter now its only lasting a day or two what does that mean?

3 weeks ago
ok she has abeen on it for 4 months but was on it since 12 for irregular period and got off 4 months before she started back on them and it was the same pills as before and it didnt do this and we also had sex the day before she got back on them for the 2nd time

If shes on birth control, that means absolutely nothing. Thats perfectly normal. With most birth controls your going to have spotting when its time for your period. It just all depends on the woman and the medication. Now if she wasnt on birth control, then she might would be pregnant. Dont worry, sounds to me like all is good.