Explaning

I dont know if this is the right group and im sorry.But Im 18 me and my fiance are trying to concieve with our rainbow baby. Which we are having a hard time doing and dont understand why we both do have stable jobs and soon to have full ownership of a house from his father. I have not smoked a single cigarete in almost 8 years and last month a couple weeks before i had my misscarage i started to crave cigaretes ive stayed away from them but idont understand why i am all the sudden feeling like im having withdrawls from it if anyone can help me understand why this is all the sudden happening it will be greatfully apprecriated. And if you also have any tips on like one a day or anything that helped you become pregnant thatd be great.