Can mild-medium morning sickness disappear, only to return much worse almost two weeks later at start of second trimester? Has anyone else experienced this?

I'm 13w2d pg today, and for most of the first trimester I wasn't been particularly well. Long story short - I've battled mild morning sickness - nausea (though no vomiting), loss of appetite, major fatigue and generally feeling blah. At around 7 weeks I had a bumper cold and chest infection that took three weeks to knock over.

At about 11w and a few days I started to feel "normal" again ... thank the Lord, I thought. But it seems to have been short lived.

Early last week I started to experience nausea again which, over the past few days, has gotten much worse than "round 1". I even threw up on Friday morning. Since then I've been nauseous constantly (virtually any time I'm awake). I don't feel like eating, and am unable to eat much ... and when I eat it generally makes the nausea worse and I feel like I want to vomit (but I haven't since Friday). The only thing that makes me feel better is laying down (and even then, not always).

I'm generally a healthy type - look after myself with correct food etc - and I didn't suffer morning sickness at all with my first pregnancy, so I'm finding this a bit hard to take and it's really starting to get me down. I've missed quite a bit of work during the past 4-5 weeks, DH is starting to get frustrated that I'm not up to doing much (I don't blame him, he's had to carry the load for a while now) and I have an active 15-month old. Sorry, now I'm just indulging in a whinge.

I'm off to the the GP later this morning, so maybe I'll get my answer then. In the meantime, I'd welcome any thoughts.

Andie