Is it safe to take contraceptive pill while on isotretinoin for the past month..also could you recommend any medicine to pre pone my periods?

Yes: There is no problem taking these two medication at the same time. Given that Isotretinoin can cause birth defects, you may want to consider using 2 forms of birth control while on this medication. Periods really can only be manipulated with hormones, so to answer your question, there aren't really any other medications to postpone periods.