A little help!

so guys today I am 4 weeks and 6 days. according to what my doctor gave me based off my lmp. and recently I have been crampy and stuff. so this morning I go to the bathroom and notice I am bleeding. I'm so scared. Idk what it is. I'm freaking out. could it be implantation bleeding? Idk. I found out I was pregnant at exactly 4 weeks 1 day. I took the clear blue test first then the other 2 a few hours later. both positive right!? so I'm excited . so the next day I go and buy some more because I still couldn't believe it. I brought the 2 clear blues. so definitely positive. I have my first appointment on the 17th. now today. I went to use the bathroom and I'm bleeding. it feels like period cramps. So I'm scared! does anybody know what it could be! im hoping I'm not miscarrying. :(