It was more embarrassing than painful but I fell right to the ground, grazed my knee and sprained my ankle. Was a bit shaken but passers by helped me up and I felt much better after limping home and having something to eat/drink. I don't think bump suffered - should I phone the doctor/midwife or just forget about it?
(moral of the story...slow down, don't carry too much shopping at once and don't take a short cut through the park when it has been raining a lot!)