Mixed emotions! Sister drama, not sure what to think!

Okay, so! My sister just announced yesterday ( to half of the family) that she is pregnant. Under normal circumstances this would be exciting news, however.....

Her fiancé doesn't have a job, they keep asking my parents for money constantly, (even though we have suggested assistance programs because we understand they are going through a rut)

They just decided a few weeks ago to stop bing polygamist 2 months before there wedding( dirty little secret my parents didn't know).

He is emotionally controlling towards her and she doesn't see it. About a month ago they decided he just wasn't going to look for a job and he was going to stay home to care for the cats (despite the struggle to afford a $500 apartment).

Pretty sure she is trying to get pregnant before me because she knows I'm trying and that it's not going to be easy for me (she also tried to move up her wedding so she could get married before after I had already selected a date).

Finally to put the CHERRY on top.... she says she is 4 weeks and hasn't even taken a single pregnancy test. NOT ONE! Hasn't peed on a stick or gone to the doctor or anything! She just says she knows!

Well I thought was pregnant too a few months ago with all the same symptoms and wasn't!

I don't understand why she would tell half of our family that she was 4 weeks along in a pregnancy she hasn't even confirmed.

Please tell me these mixed emotions and frustration is justified!

I just really need my emotions validated when I'm having an internal battle of emotions over having a hard time conceiving.