U are fine while u are pregnant to put whatever on. Just make sure once baby is born if ur breastfeeding u only use what is safe to go in babys mouth.
I use coconut oil. No problems.
I use Lanolin cream. Safe for breast feeding moms. It's like thick Vaseline. My nipples were very cracked and itchy and my OB told me to get that and continue using it once baby is here.
i have been putting on lotions and nipple cream for weeks now. mainly as my breasts grew my nips became very sore, dry and crack and was advised it was the way to go. now i only put on once a day!
I think it's fine. It's good to moisturise nipples up until birth so they aren't dry and start to crack.
I don't think it matters, I mean if your skins dry or something. I have really dry skin so I lotion my entire body everyday.