Which paper do you mean? Either there is a problem with the journal without medline/pubmed listing or the research is new and currently published. It takes months to years for citing....
making sure you use the right keywords may help in the future So that if someone is search that particular topic under a keyword your article will come up. One suggestion is to have a look in punned and the MESH terms and explore what other words or terms you can include so that you can reach more people.
Usually it takes a while until your work starts being cited, and this also depends a lot on the research area in general and the "hotness" of the research topic in particular.
In addition, your work may be often cited if
* your ideas/methods are easily transferable/extendable to other problems;
* your paper is written in a nice expository manner and is likely to be easily understood by the colleagues;