Pregnant pause: to sit or to stand

I was confronted with a dilemma today. And it is not the first time I have come across this particular dilemma.

I was sitting on a bus on the way home from the City. In front of me stood a woman of about 30 years of age. With a slight bulge for a stomach.

Now, the problem is this: do I assume that she is pregnant and offer her my seat? Or do I assume she is not pregnant and remained seated. If I go with option A and I am wrong, I have just called her fat. If I go with option B and I am wrong I am the low-life kind of guy that does not offer a pregnant woman a seat (I do not see many London women offering their seat to pregnant women relative to men, oddly enough - you would think the empathy factor would kick).

So what did I do? When in doubt do nothing, I always say., , ,