Diagnosed with severe tonsillitis prescribed penicillin v to take 6 hrs apart for 10 days, often get vaginal thrush from abx, can i take probiotics when on pen v to prevent candida overgrowth? or have them a few hours after my pen v dose?

Yes - this is a somewhat common side effect from antibiotics... you might develop vaginal thrush. You can certainly try the probiotics - hopefully they would have an effect. I prefer to get my probiotics from food: yogurt, sour kraut, sour cream, kimchi, cottage cheese and others a few of the foodstuffs that have them. Or you can just buy some in the 'yogurt' aisle of your local shop. Good luck!