Starbucks's drinks

I'm in love with startbucks but had a previous miscarriage and I believe it was due to a lot of caffeine I was drinking (not just coffee) now I'm in love with the black Iced tea with mango syrup NO LEMONADE (lol) I will be avoiding frapuccinos and all of that but I was wondering if that Iced tea in general is a big no no during pregnancy? I've read about the hibiscus (which I was also drinking)  I had no idea about any of this so I'm really trying to take precautions 4 weeks 5 days pregnant ❤