Puppies, it is best to avoid all non-steroidal anti-inflammatory drugs when TTC. NSAIDs (naprosyn is one, so is ibuprofen) tend to suppress ovulation and can interfere with implantation. If you need something for pain, paracetamol and codeine are fine both when TTC and when pregnant (so says the IVF clinic). Basically, it's best to stick to things like panadol or panadeine if you need pain relief.

BW