Exercises for Tightening Pectoral Muscles After Breast Implants?

I had breast implants about two months ago. I was told by my doctor that I was borderline of needing a lift with the implants. I chose to wait and see what the implants would do. I was wondering, are there chest weight lifting or exercises that I could do to help tighten my pec muscles, to help lift the breast a little higher? I think if I could tighten my pec muscle just a little, my breasts would be at the level I want them to be. I would like to wait on a lift, if possible.