Do I need implants?

I am a 36C- however I noticed lately after I lost about 15 lbs, that they have lost some volume and look saggy ( without a bra). It bothers me, and I am trying to determine if I should get implants or not. When I lay down, they look flat, I want they to stay perky and not fall to the side. My boyfriend loves , but am afraid of all the risks . They look great with a bra, but I want to look good without one too. Have you had a similar experience? was it worth it ? Thanks