The lipton stuff is raspberry, not raspberry leaf.

That's one of my favourite flavours as well. The raspberry leaf tea is the one that people use in the third tri as it supposedly strengthens smooth muscle and makes your contratcions more effective. So the raspberry should be fine - I would drink it without any qualms.

If you want more opinions about the raspberry leaf tea - there's a few discussion threads in the third tri general discussion. Personally, I am a fan.