Thinking about delaying IVF #2

I am thinking about delaying IVF #2 until April. I really want to lose 30 pounds before I get pregnant. I want to be as healthy as possible. I have a fear that if I'm successful at getting pregnant and am unhealthy that I won't be able to carry the pregnancy to term - especially if we get pregnant with twins. My cycles are like clockwork - 28 days exact - so that would put us at April 14th with a late January due date. That is a couple of days after we get back from a cruise we have planned to Mexico with the fam. I would love to be smokin' hot and wear cute outfits, drink, and have lots of fun being active. I wouldn't be able to do those things if I was pregnant. If I went ahead with January IVF, I would be around 11 weeks pregnant and paranoid. Cam doesn't want to delay, but I think that he would be happier with the outcome if we did. Still undecided, but that's where I'm leaning. I watched a show called biggest loser and they have me super motivated. I could really do some damage in 15 weeks.