Oh it must be such a tricky situation......emotions will be quiet raw at the moment and they will be grieving... maybe some time is needed, but if you're sister only lost her baby a couple weeks ago and you're 12 weeks pregnant its not like you intentally went out and got pregnant just to hurt her.

I know the hurt you can feel when you have lost a baby (well not at that late stage) but when you see a pregnant woman or a family member pregnant....you are grieving and want you're baby back and then you see a woman pregnant and want what she has...but thats not you're fault.......i personally dont think you have done anything wrong at all, it might be hard for her to see you at the moment, but i dont think she or you're other family members should blame you just for being pregnant. Sounds liek you are a very understanding and caring person so they should understand you havent gone out of you're way to hurt anyone.

All i can say is give it some time and maybe try and approach it later on.....it might be hard for her for quiet a while..even throughout you're whole pregnancy...or maybe if she falls pregnant again it might ease some of it.

Thats my personal experience anyways. Dont know what it is like to loose a baby that late in a pregnancy. I lost mine at 9 weeks...