27 weeks LMP today?

well according to several websites (eg www.i-am-pregnant.com), my wife has reached the thrid trimester today! woo hoo! (although some believe it starts at week 28 LMP)....she went to the doc yesterday as she noticed a decrease in kicking over a 24 hour period...so the doc put her mind at ease saying that if she gets 10 movements in 24 hours then she's ok..some babies kicks even less than that on some days..which is reuring...my main question today is...what can my wife expect now over the next 12/13 weeks...is there anything in particular she should be doing (she goes for a 20 min walk every day)...next doc appointment in 3 weeks, then hext hospital appointment is 2 weeks after that...thanks in advance