I'm almost 35 weeks, and baby's head down but definitely not engaged - he was lying diagonal just last night.
Gem13, it depends on what method your midwife uses. Some midwives say 2/5 when only 2 out of 5 parts of the baby's head can be felt when she prods around. The rest - that is, 3 out of 5 parts, is engaged in your pelvis.
Other midwives use the opposite method - by 2/1 engaged, they mean 2 out of 5 parts is engaged and the rest of the head can still be felt outside the pelvis.