More than likely you have pulled or strained a muscle or ligament. However there are also some other conditions that could be considered. onwe being plantar fascitis (fallen arches).
It could be mostly plantar fasciitis. It is the inflammation on bottom of the foot. It usually affects the heel those who are overweight they face this problem.
It could be tendonitis. If your shoes are tight, they can irritate a tendon, causing side foot pain. Try wearing a wider width of shoe. If pain continues, ask doctor.
