Honestly, just smile and nod and take it. Continue to express how sexy you think she is, even if she says "You're full of it". Be there when she needs you there, but also make time for yourself. When you do go out, though, make sure you check in; if she's letting her emotions tell her that you may cheat, then that will be enhanced if you don't check in regularly.
Her hormones may level off as she gets farther along, but they also may not. So, just try your best to handle it.