Are sleep aids safe to take while breastfeeding? two weeks postpartum?

You would need to discuss which sleep aids you are talking about. Most of them will cross into your breast milk, therefore I would recommend against.

Everything that you ingest can potentially pass in to your breastmilk. Most sleep-aids contain sedatives that are not at all safe for a two-week old infant. Given how recently you gave birth, the safer way to obtain sleep is to sleep when the baby sleeps, get a breast pump to allow others to feed the baby in the night if you choose, and avoid all stimulants such as coffee, chocolate etc.