Sister is dealing with infertility and I'm pregnant

My younger sister (which is literally my bf) has been struggling with infertility in almost 3 years now.

I've been thinking about getting pregnant for about a year now, but kept stalling just because I felt I couldn't do it to her.

Eventually, we did started ttc'ing, and surprise surprise- I got pregnant on the first try.

I'm now 5w5d pregnant and after consulting with my mother we decided to tell her right away.

We did tell yesterday, and at first she seemed happy and understanding, what later developed into tears (which is perfectly okay of course).

Unfortunately, today I called to see how she's doing. She reacted very badly, telling my she might not be able to ever talk to me about my pregnancy, or ever be able to talk to me ever again.

I understand this is an emotional reaction that I shouldn't necessarily be taking seriously, but I'm very hurt and basically hopeless.

Did any of you ever experienced something similar? Please let me know how things turned out and what is there for me to do?