Bitter about my pregnancy

So my cousin is getting married next year (she got engaged in October 2015) and asked me to be one of her bridemaids because we are/were so close. Her only 'rule' was that no one was allowed to get pregnant or engaged until after the wedding. I'm 27 and my partner and I have been trying for a baby since (September 2015) and I found out last week I'm pregnant. I never promised here I wouldn't get pregnant she just assumed as it was 'the only thing she asked from us girls' that we would all abstain/not get pregnant. I was so scared to tell her and as expected she flipped told me she would have to drop me from the wedding and there was no point in me coming on Saturday with her and the other bridemaids to try on her potential wedding dress and go for cocktails, she doesn't want to be around pregnant ppl. Then she kinda backtracked said congrats and I went to see her we didn't mention how she was on the phone. Anyway now she's blaming me for getting pregnant and has admitted she is feeling bitter about the whole situation basically I'm the only person in her life who hasn't had a child yet and her and her hubby to be have been told that because of his sperm quality he wouldn't be able to have kids (they have tried for 6 years but I keep telling her it can still happen and do t give up hope) things got out of hand she told me she thought I would understand the pain she goes through when someone close to her is pregnant (her close cousin has had 5 kids her sister had 6 and all got taken away from the social) she said she just got all the baby stuff out of her head and now it's all come back and made her realise how much she wants what I'm going through but can't. This has stressed me out so much my partner rang her and she was crying he felt bad for her but all she kept saying was 'it was the one thing I asked' now I haven't gone with the bridesmaids and we haven't spoken it's so awkward the engagement party is in August but I just don't know where we can go from here 😔