Drove to Manchester this morning, about 25 miles ish, noticed a bit of smoke coming from front of car, on the passenger side. Pulled over and checked under bonnet, coolant was below minimum. Put water in it from garage and carried on. Pulled up ten/fifteen mins later, coolant had dropped a bit. Drove again for another ten/fifteen mins. Smoke again. Coolant below min again. Car runs fine. Nothin on dash indicating anything wrong. Dipstick and oil filler cap look fine. Am I gonna do damage driving home? What should I do?