Seriously? Who doesn't stand up for pregnant women on the train, especially when asked and in a priority seat. What is wrong with people. As an aside, do you have one of those 'baby on board' badges. That helps: sometimes when I'm not sure, I won't offer my seat just in case!

Meanwhile, as far as the P4 goes, if I do need to use it, I'll rely on the TFL live departures page: put in the stop you want and it'll give you a pretty accurate arrival time. I only leave the house when it's a couple of minutes away. Would that work?