I am 10 weeks pregnant but I am not gaining weight. I am losing weight instead. I have lost my appetite and I don't eat too often because I feel sick every after eating. I get persistent lower back pains. I sometimes get belly cramps, I can feel something hard on my belly. And I feel weak. Is this normal?

Pretty much.

Many women get sick during the first 3-4 months of their pregnancy, and find it difficult to eat. Try freezing some grapes and eating those, they may go down more easily than regular food. Also, isotonic sports drinks will often settle your stomach enough to let you eat a small regular meal. Think "little and often" with your food. Don't wait until you are hungry, if your stomach is not misbehaving, eat something small.

Many women do lose weight in the first trimester, and only start to gain it back in the second. This is normal.

Tired and crampy and back pain are all things that happen in pregnancy.

I suspect the hard thing you are feeling is your uterus. Is it hard and roundish and low down and easiest to feel when you are lying flat in bed?

Yes it is.. is that all right?

All sounds normal to me. That's your uretus, which will get bigger as you go on. One of the coolest things about being pregnant is when you start feeling the baby moving around instead of just a hard lump.

Go to your ante-natal checks and let your midwife reassure that things are fine, but so far, all the things you've described sound pretty normal.