Is Norethisterone With Champix Contraindicated?

im 36 and been having continuous period with only 1 or 2 days break here ant there, im under a lot ofstress at the moment and my gp believes this is the cause of the prolonged bleeding, i am also taking champix to give up smokeing, my gp has given me norethisterone for 3 week which finished 3 weeks ago, can i now use norethisterone at the same time as champix, im sightly anemic, asthmatic and only weigh about 8 stone