Hi I Have A Question As To What I Should

Hi i have a question as to what I should do now but over a month ago I missed one of my contraceptive pills which I ended up taking the next day. Since then I started to spot but then I also changed my pill as I was on 50mgs due to heavy bleeding and serve pain and started taking the 30mg instead as nothing was stopping the pain. I started that it straight after I finished my old packet. My question is it's been a month now and I am still spotting and have started getting my serve cramps randomly.At times the spotting is not heavy at all but then can become heavier. Should I stop taking the pill all together and wait to start fresh or will it stop once my body gets use to the lower mg ?

Thank you