Hopping over from WTT to give you some advice, hope you don't mind! I'm a nurse. Magnesium sulphate paste is perfectly safe to use in pregnancy, no issues there. It'll come in a little plastic tub, the paste is white and very thick. You'll find it helpful to let the tub sit in a bowl with an inch of boiling water, it just softens it enough to make it easier to apply. The heat in it will also be good to (TMI) draw what is inside the absess out. Having a dressing to go over the top is a must too, so that it keeps the paste in the right spot, so the paste doesn't go on your clothes and again TMI, if the paste does what it is meant to, you'll have some stuff coming out the asbcess too. Hope this is helpful and I'm not out of line posting this. Wishing you all the best for your pregnancy x