Unsure of pregnancy

Brittany
I've been on the IUD for 4 years I got it removed in january and I have been trying to conceive, I have been having regular periods since having IUD removed but last month my period came on 2 times and only 18 days apart, at this point I don't even know when I'm suppose to have my next period or what's going on w/ me! Has this happened to anyone or do u know what the issue could be??  I was expecting my period on July 2nd but with me having 2 periods last month I'm really unsure of what's going on