There's a link between newer contraceptive pills and a higher risk of serious blood clots, according to a new study.

Researchers at Nottingham University in England say users of any combined oral contraceptive are at an increased risk of serious blood clots.

But they found the chances were higher with pills containing one of the newer types of progestogen hormone.

But the study stresses that oral contraceptives are safe - and that women taking them shouldn't stop, but should talk to their GP if they're worried.