Think of all the women who get pregnant while they're carrying around toddlers! Granted, they're not infertile, but I think the 10 or 15 lb limit is just to make sure we don't overdo it. I've also seen women post on here about lifting luggage after they cycled overseas, and they were fine. Good luck with your 2ww!
Two days after my transfer I traveled 20 hrs home by myself (hubby had to go home early due to work), lugging/lifting my heavy carry on by myself. I was nervous since I had my laptop, meds, etc in it and it was heavy. The following day (3 days post transfer), I fell down some wood stairs - my feet went above my head and I landed on my lower back (uterus level) and hit four stairs on the way down. Needless to say, even all that didn't affect anything (twins).