I'd still go for it (but that is just me). The OP states he/she is arriving before the six month period (if that even matters, as the subject of many debates in the past) and he/she is leaving exactly on the 6 month window. Getting stuck in a US airport on the way down? Ernie is more likely to be elected president.
Getting held up on the return?Two points:
1)That is about as likely as Jesse being elected Exec Dir of UPI or AP
2)I'd love to be able to call my staff and tell them I could not come home