If you've got proof that the patent was filed you should be ok.
All information about the product - including the actual product if it is marketed before the patent is granted - should be marked Patent Pending.
You can then charge royalties [including back-royalties] from anyone who copies the conception.
Mind, to mark anything with patent pending before the patent is filed in an offence in most countries and can lead to your invention not qualifying for an eventually patent.
I know it costs a lot but once you are ready to present your invention to possible partners/manufacturers, these dealings should be done through a solicitor for your own security.