Am I being stalked? Should I be concerned?

Today I was out In my back yard tanning (in bikini) and a truck that had been in the church directory right behind our house and the small church next to our house, drove by once, noticed me, then took a while turning around, out of my sight,. then drove back slowly, and left, I went back inside and about 25ish minutes later went to take my dog for a walk, as I walked about two blocks from my house, I saw the same truck driving behind me, we got to the corner at the same time, he stopped at the stop sign about a minute longer than needed, considering there was no tragic, and proceed by me slowly, then stayed close behind me or in front until I took another turn and he went straight, then about another two block from there on my way back to the house, he passed me again. He is a younger looking man; yearly 30's, a clean cut; cowboy type,. I'm just worried because he knows where I live, is it something I should be concerned about? I'm under 18, and female.