It’s called a dryspell, and it happens to everyone. There are many ways to make sure it won’t return, however, and that by using DR aid foods, or getting a more regular sleep schedule. Lastly, remember that everyone dreams multiple times a day, and it’s only a matter of putting yourself into the right frame of mind (it helps staying still in the same position you woke up from) to start remembering. LDphone wrote a nice guide on it. Last but not least, you can always anchor dream recall.
Dream on. 