Low Platelet Count. Readings Show 299. Work Out Thrice A Week. Have Further Testing Done?

I had a low platelet count 78, had mild headache for three days felt weakness for a few days. The following day of the blood sample I reapeted the test in an other lab. They took two different samples one was the regular sample red cap vial and a second was taken on a blue cap vial. The lab technician response was that some people that usually get low platelet results; sometimes have some type of reaction to the substance on the regular vial. She mentioned that she will double check with an extra blood sample taken with blue cap vial that has another substances. She uses a multipler factor to correlate results, readings were higher 299. I am concern with this because this is the second time it happend to me, last year I went through a similar situation. However I do not remember having low platelet in yearly teste in previous yearly examination. I am 62 years jog 3 miles 2 to 3 times a week, go the the gym the same number of days during the week an play tennis on the weekend. Have any idea what could be happening to me, should I have further testing done? I will like to have an Hematolist opinion if possible.