Thrombocytopenia - Low platlet count 35K

Hello All, My fatherinlaw has been affected with Covid positive and we found the platelet count was initially 47k 15 days back thru the blood test. But not sure this was his existing issue as he didn't check the blood test for 2 years. During this time it was 47K, 52K, 35K, 29K, 32K, 48K, 88K, 76K, 33K and now finally yesterday's report shows 34K. He is not bleeding at this time and he is stable but wanted to know it will affect any serious problems. I am trying to take him to hematologist but not sure when the RT PCR will show as negative - it's been 17 days since he tested positive. I heard hematologist will check only after he gets as Negative. Can someone help me when he will get Negative and what can we give as home remedy until we take him to the hematologist? PS: I am not sure how to contact the doctors here for sharing the reports.