Why does One Blood keep calling me?

I don’t answer phone calls from numbers I don’t know, and this number kept calling me, so I looked it up and it’s a number from One Blood. I gave blood last week and I’m worrying that they’re calling to tell me I have HIV or something, they haven’t done this before, and I don’t know when they’ll call next, if at all. Why would they call me?
Answers

AVDADDY

They want more

choko_canyon

To make sure you had no ill effects from the donation, and to encourage you to come back and donate blood again. Why don't you maybe call them back and ask, as if you were over the age of 12?

Anonymous

Not sure. Email them if you don’t want to calll them back