I was on 6-mp for almost 10 years. I was only taken off it 2 weeks ago.
I didn't find any side effects with it. (except 1 that I didn't know about, read my thread in the support forum)
I got my regular bloods, and nothing ever came up.
I was told at the time I might be susceptible to colds and throat infections but they never materialised.
Don't worry and hopefully it will give you some kind of remission.