Latest figures from the Assembly government show 922 girls under the age of 16 were recorded at clinics in 2005-6, and five of those were under-13. And 6,500 women in all age groups attended clinics for emergency contraception - a 10 percentage point rise since 1995-6.
Wales already has one of the highest teenage pregnancy rates in Europe and cases of sexually transmitted diseases are also on the rise. However, some headteachers were blamed this week for still not putting personal and social education at the top of the agenda.
Swansea has been praised for good practice in reducing teenage pregnancies, including a community service of handing out condoms to children aged 13 or under.
But Mark Campion, PSE adviser for schools in the area, said there was still resistance to placing priority on lessons that send out a safe sex message.
"Our success so far in addressing teenage pregnancies has been down to us treating young people as individuals," he said.
"But there needs to be a more specialist approach in secondary schools, where a small team of dedicated, capable and committed teachers can give the lessons."
Schools also need to tell young people about services that can help them, he said.
David Evans, secretary of the NUT Cymru, said the statistics were worrying.
He agreed schools have a role to play in educating children. But he also said parents should be more involved.
"Teachers have a duty of care over any issues that may affect their pupils," he said. "They should ensure that children are educated appropriately on the dangers of unprotected sex."
NUT Cymru wants more support networks to encourage girls who fall pregnant to keep studying, including school-based crech s for both teachers and pupils.
The latest figures on teenage pregnancy in Wales show a fall in conception rates, from 9.6 per thousand girls aged 13-15 in 1999 to 7.5 per thousand in 2004.
Initiatives like the Books and Babies scheme for teenage mums in Rhondda Cynon Taf are running in some of the most deprived areas of the country.
But the organisers admit few return to school after having their children.
Just under two-thirds of all men going to the clinics last year mainly for routine contraception were under 19. Of those, 1,198 were under 16. The number of boys seeking contraceptive advice under the age of 13 was 59.