Talk to your doctors about the length of time. I always add a little longer to be sure. The doctors can also rx something to help get the mthx out of your system.
With my first I didn't go in to remission, but I didn't have any flares. The strange thing was, my immune system was like an iron door the whole 9 months - that may have something to do with it. I went in to remission with my 2nd child. about 10 hours after having him, my RA came back 10fold. I haven't been the same since. It was a rough pregnancy, I was very ill the whole time (pneumonia, bronchitis, etc.) but, my arthritis was completely pain free. Go figure.
I will say, so as not to scare you too much - I planned my 2nd WAY too close to my 1st (concieved 8 months post 1st), espeically considering the 1st was a c-section and knew I'd have to have surgery again w/the second. That may have something to do with what happened with me. Every pregnancy is different, so you never can tell even with your own body.
How your body reacts to pregnancy (including remissions) is actually due to how your body reacts to your husband's DNA, I'm told. So, morning sickness and all the other pregnancy woes really ARE the man's fault! But, remember to THANK him if you go in remission! ha ha!
Good luck, and remember, stress is sometimes worse than all these other concerns/issues combined!