I need help...

ive been trying to get pregnant for almost 6 months.. I got my birth control removed back in may of this year.. (IUD) and I haven't got prego since then... my man and I are getting disappointed every month.. him and I have sex like no other.. I'm starting to think I'm doing something wrong here. the frist time I got the IUD out I got prego within the frist three months.. we have a 5 yr old and a 3 year old... we want other one.. my question is how long did it take y'all to get pregnant after second time having the IUD in? I feel like I'm pregnant.. I'm moody my boobs hurt my food habit got bigger my tummy is bigger I'm not giving up... please help me easy my mind.. I took a test its faint but my blood work said no. I'm lost please help...