My sister lied about being pregnant

My sister went to the doctor yesterday for anxiety and she told me they put her on some type of medication and then also put her on Xanax.

Then today she snapchatted me while I was at work and she asked me if she told me about how her blood test had gone from her appointment. I said no and she then told me she was pregnant using this picture

And then saying “surprise”

Right off the bat I had a feeling she was lying considering there’s no way the doctor would have put her on something such as Xanax if she had just done a blood test showing she was pregnant. So I told her if she was lying then that would be really really shitty of her because that’s not something to joke about. She kept insisting that she wasn’t lying and saying that she was serious and that she was being “for real”

I stopped responding because I was driving and she then snapchatted me again saying “okay fine I was kidding” and then went on to tell me that she just has a vitamins deficiency

I don’t know if I’m over reacting but I’m actually livid right now

I haven’t had a period in 7 months and have fertility issues and she sees NOTHING wrong with lying to me about being pregnant

Please let me know if I’m over reacting because right now I can’t even respond to her because I’m going to lose my shit