Early pregancy

So I have recently got my BFP but this was before my period was actually due because I had an idea I was pregnant beforehand but the one thing I never actually heard was the anxiety finding out that early on is, statistically this is were about 70% of miscarriages happen and for most people, they don’t even realise it’s happened because they weren’t aware they were pregnant but I’ve been having horrible cramps and I’ve been running on and off to the doctors due to me being extra worried, can anyone else say if they got any bad cramps between 4-7 weeks??

On another note I’m 20 years old and relatively healthy but does anyone know the statistics for miscarriage at my age?? Trying to ease my mind a bit.

Thank you x