Couch to 5k is a running program developed by Josh Clark who wanted to make his mum get up from the couch and run. So, run but if you are pregnant do not race. If you notice your heart rate spiking then it means your baby's heart rate is racing too. If you struggle to breathe then so is your baby. So if you want to run a local 5k for fun then do so without putting unnecessary stress on your baby.