Hi Kerry, I'm an OT and have dealt with foot pain from time to time. You haven't really given enough info about the type of pain you're experiencing for me to offer a real theory but there are a number of things it could be.
Some people have mentioned plantar fasciitis below, this tends to be located within a specific area of the foot, typically the heel, and the pain may not match either side. You are at more risk of developing this when pg as you're carrying extra weight.
Also when you're pg your body makes hormones that relax you which is great for your pelvis stretching when baby comes out but it also puts your at greater risk of soft tissue injury. If it's this kind of pain you will feel it inside your foot rather than just on the sole.
It may also be that your extra weight has made your feet sore perhaps combined with not wearing supportive enough shoes.
I would recommend you speak to your midwife who can refer you to the antenatal physiotherapist who will examine you properly. If the pain is very serious they may be able to give you some crutches temporarily. In the meantime your GP can prescribe codeine for you in pg if paracetamol isn't helping. While waiting for appointments keep off your feet as much as possible and wear flat soft shoes like trainers, not hard flip flops/sandals - you want some 'bounce' in the sole. If the point of pain is very specific you can buy some cheap foam insoles andcut a piece out where it hurts - this should relieve the pressure a bit on that point.
Hope this helps, feel free to ask more questions.