Hello koike6 and welcome to NeuroTalk.
I used to know all the blood values when I was still a registered nurse, but with not working and a chronic disease that affects my memory, I don't remember the exact normals for any of the blood components any more.
I do however remember that the values that you mentioned are far from normal.
43000 then dropped back down 20000, which is still not bad it was at 3000, for about 1 month.
Do the doctors know why your platelets are so low? Is there any treatment that will help? I certainly hope that there is something that can be done, as I daresay you'd be rather frightened all the time of cutting yourself. Even the teeniest nick could turn into a major haemorrhage, but I suppose you already know that.
Welcome again to our forums. I hope you get the answers that you seek.