Trying to conceive but nothings working.

Tiff
Me and my bf been together a good 9-10 years well went from best friends to lovers within 6-9 but we have been trying for a year now and nothings working we both have 1 child he has a daughter I have a son we are 20 yrs old I had complications with my son when he was born had an emergency csection and then had the IUD mirena after that but had it removed after 2 years of problems with it. But now no birth control no condoms. Periods irregular. And only 3 days every month. But any suggestions ? Please help?