Need advice there is 2 questions in this so read slow

Amanda
Ok first off I keep losing the weight I lost another 10 pounds in 2 weeks what can I do I do a lot of eating so I don't get it at all I'm 22w5 days right now????
This is the big one also so my boyfriend and I have a son together he is 18 months old his famous little family don't like me and keeps saying that he is not his when we were pregnant now that he is older they don't say it anymore wel now we are pregnant again and this time we are having a girl they told him it's not his because it's a baby girl now and that he can't have girls because his 2 other kids from another girl are boys plus our 18 month old son what do I do he wants a DNA test for our daughter any help please