Visiting my US Girlfriend, Have Serious Questions

[Clegane 0]

ello there, I wasn't really sure where else to post this so sorry if I posted this in the wrong section or anything. I'm a 21 year old canadian Male who is currently unemployed and not in school. I'm planning a trip this july to visit my girlfriend who lives in North Dakota. I previously went too visit her this April and had my fingerprints and picture taken. I was then pulled over for secondary inspection. because I guess my situation seemed suspicious? I waited for 30 or so minutes before I was called up and asked a few questions. After I was handed my passport they sent me on my way. Will I be flagged everytime I re-enter the country to visit my girlfriend? I understand that I'm currently not working and not in school, but does that mean I'll be pulled over every time for second inspection?

I'm planning on visiting her again this july for 2 months or so, And i'm kind of worried that I might be denied entry or even worse. I was just wondering if you guys had any tips or suggestions on things I could bring with me to prove that I do indeed have ties with my country? I don't own a car and I still live with my parents but I do own a bank account and collect tax returns. Would a letter of invitation from her parents help at all? Could I bring or say anything that shows them I do plan on returning home?

I also read up online that Canadians are usually not required to have there fingerprints or photos taken when entering customs. Was there a certain reason why mine were taken? Did the Customs officer think I was suspicious or something?

Thanks for reading my post, this whole situation has me so nervous for my next trip that I'm losing sleep and having nightmares left and right. Sorry if it's in the wrong section of the forum but this is the only place I could guess where to post this.

Thanks and have a nice day.