Has anyone else had a problem with the Loestrin birth control pill?!

I've been taking it every day for almost 4 months now. The problem is that ever since I've started taking it, I've been getting my period almost every other week! Sometimes they will be within 10 days of each other. They are really light but they usually last for a whole week.

I know that when you first start taking birth control pills, your period can get irregular, but how long does it take to become regular again?

I do have a 5 month old baby, but I don't know if that could be a contributing factor to all of this. Before I had my baby, my period came regularly at once a month.

Thanks for any help!