There's no problem with immunity and breastmilk - the baby will get all the good stuff when she is born without expressing now. Just get that swab done so if you do test positive to flu A you can be monitored. It is necessary for the safety of those that you or your kids come into contact with. Remember the first run of H1N1 is much milder than the 2nd and third waves.

For me I actually stayed FLU A positive for 6 weeks - I was really shocked when my swabs came back positive when I was hospitalised prior to Miss I's birth... This of course then put everyone in the maternity unit at risk I felt awful...