Hi May,
I think it's important to continue to participate in the sports that you love both during and after your transition. It is possible that the reaction of your teammates may be non-supportive, but hopefully you'll have a positive experience, similar to mine:
I began my transition in 2010 and at that time I had been playing hockey for 20 years. I was extremely worried about coming out to my hockey groups. I definitely wanted to keep playing (hockey is an amazing sport and I love it so much), but I wasn't sure if I'd be accepted by the guys that I had been playing with for the last 5 years. (we had a couple of girls play occasionally, but the group is 98% guys). I prepared myself to be rejected, but I asked to speak to everyone in the locker room after our last game before Christmas break 2009. I explained to them that I had been dealing with gender identity issues for a long time and that I had finally decided to live my life as my true gender, but that I also loved hockey and wanted to continue to play with them, even though I would be living as a female. Most of them were speechless, but unbelievably some of the guys were very supportive, wishing me all the best, telling me I was very courageous and that yes of course I would be welcome to play. "Man, Woman, doesn't matter, you are still a good player and we want you here!" one of the guys said. For the next 3 years I continued to play with them and received nothing but support from everyone, the only difference was that I changed in the female locker room. Eventually, I had to move for work reasons, but I found a new co-ed group to play hockey with in my new location. I wasn't sure if I was going to have to explain my situation to the new group, but everyone just accepts me as a woman and now I'm just one of the girls both on the ice and in the locker room.
Good Luck with your rugby crew.