Will Loestrin 30 Help To Stop Vaginal Bleeding?

I have been on microgynon for about 4 years and not had any problems. I've started to have constant bleeding/dark discharge - I think it started when I ran 2 packs together but then when I took a break and went on to another pack it started again. My doctor has now prescribed me loestrin 30 to start taking immediately after my microgynon 30 finishes. I'm going on holiday and really really don't want this to carry on and on. How likely is it that loestrin 30 will stop my bleeding?