Period jumps to right end of text in arabic language

Hi, we are currently translating a site to Arabic and need advice on the following issue:
Arabic is written from right to left so the period at the end of a sentence should be at the lefthand side of the sentence. For some reason, the period jumps to the right where it should be in European languages. It works fine if the period is in the middle of a text, but if it ends a text, it jumps to the right. This is a very strange issue that we don’t understand. Maybe you can help us out.
Thank you.