Currently 12w
I went out for a meal last night with a friend (a huuuuge deal, as this is the first time in 6 weeks that I've felt well enough to drag myself off the sofa and out for a night) and we had a lovely pizza on a terrace outdoors where - it only gradually dawned on me - people were of course smoking. It only got really bad towards the end of the meal when a couple sat at the table next to us and both began to smoke, and we left about 15 mins after that. But over the course of the evening there probably was a fairly constant but mild stream of smoke from around the terrace.
We were out in the open air which probably helped dissipate it but I am worried that I was stupid to stay out there.
Stupidly it didn't really occur to me right until the end - I just felt so happy to be out and seeing a friend and feeling normal again that I didn't really notice!!! 
DH is telling me not to worry as (probably right) all our parents probably sat around in massively smokey atmospheres in the 1970s when pg with us... but I am worried... I won't do it again obviously but was I very, very stupid? :(