the Messenger of Allah ﷺ used to pray while. I was by his side in the state of menstruation. Sometime his cloth would touch me when he prostrated. He would pray on a small mat.  

كَانَ رَسُولُ اللَّهِ ﷺ يُصَلِّي وَأَنَا حِذَاءَهُ وَأَنَا حَائِضٌ وَرُبَّمَا أَصَابَنِي ثَوْبُهُ إِذَا سَجَدَ وَكَانَ يُصَلِّي عَلَى الْخُمْرَةِ