Talk to General Physician on Low Platelets Count

I was struggling with weight gain, some doctors suggested that i may have hyperthyroidism i did tsh,t3, t4, free t4, t4 was very little more than usual. so doctor suggested me to go through different tests like CBC,vitamin D and ANAG. I was surprised to my platelets count was low as 64 because i was feeling completely normal. ANA is also positive. No idea which doctor to see ? doctor also suggested i may have spleen issue