Is this a normal fluctuation for platelets? 9/14/21-210 x 10 ^ 3ul, 10/8/21- 213 x 10^3ul, 10/14/21- 211 x 10 ^ 3ul, 11/5/21- 196 x 10 ^ 3ul. it seems like a big drop. i had pharyngitis could this cause the drop?

This will depend on time of day, how long you have been out of bed and lab used. I always figure a 10% variation of most labs done on the same day from the same tube as usual variation. Thus 10% of 210 is 21 and 210-21=189 so that looks pretty good just on one day but as it was over almost 2 months would consider range of variation OK. But check with local lab as they may have varying variation

All laboratory results need to be interpreted in the clinical context and the doctor who ordered the tests is usually in the best position to do that. Talk to the doctor who ordered the tests. Having said that, the data you provided is not a cause for concern. Wish you good health!