Is this foot or a clot in my extraction site?

Had a v difficult extraction of my remaining lower left molar today with a stitch because they had to drill into the bone and cut the tooth to remove it. I never bothered looking in my mouth after. I’ve since eaten and on looking at it now it looks and feels like there is a white lump of food in it. Or is it the clot? I’ve swished with salt water and it’s not coming out. What should I do?