Is this probable cause?

Yesterday I was pulled over for running a red light. As the cop come to the window I was nervous I gave him my info and he went back into the car when he came back he asked me if there was any drugs, alcohol or weapons in the vehicle i said no. He asked if he can search the vehicle and I said no aswell. I asked him what is the reasoning to searching my car I asked does it smell? He said no it doesn’t. The cop then says you are acting very nervous I think there is something you are hiding and I said I’m just nervous from being pulled over. He then says that he can see specks of marijuana on the floor and that gives him probable cause. So he asked again and I just gave up the paraphernalia I had in there that was in my glove box not in view he took that and some dab in evidence but nothing about the “weed” on the floor which I don’t believe to have seen any and only charged me with paraphernalia because of my cooperation. Is this legal the way he handled the situation?