I kind of got that wake-up call today too! Went out in the lake for the first time this year and had some coughing trouble and couldn't get my breath after the first 2/3 was through. Hmmm...
Got on the bike, and as long as I didn't have to breathe hard, was ok, but any uphill just wiped me out and I couldn't stop coughing stuff up.

I had something similar last year on my first lake swim. Some kind of pulmonary edema / asthma or something. It's the only two times I've ever experienced it. Kind of freaks me out.

So -- mine is in 4 weeks -- oly length, also.
Here's hoping we both get a PLEASANT SURPRISE on race day and things go just fine!

Good luck! Keep us posted.
J