I'm scared

So after 2 years of trying we finally got the BFP, yay! 4w6d.
Only now I'm freaking myself out because I keep getting cramps and I'm scared every time I feel discharge (tmi sorry!) that AF has arrived.
I'm scared that I'm gonna get my hopes up and then find out I'm not pregnant.
I've got an appointment with my GP tomorrow so hopefully they can put my fears to rest but I'm just so scared that I keep wanting to cry.
Just needed to let it out sorry!