How to tell my parents

Last Wednesday my boyfriend and I found out I'm pregnant, we've been together 4 years this may and were already planning to get married on our anniversary before we found out about the pregnancy. We aren't doing a party or anything like that because we just want it to be a simple and very intimate courthouse wedding and a dinner after just us two. He's 20 and I turn 20 in July, both have good jobs and went to college he went for welding and I went for cosmetology. My parents are Mexican so they are pretty strict and it's really scaring me to tell them. I'm only 7 weeks but I'm a small girl so I will definitely start showing fast, plus my eating is getting out if control and I'm always nauseous with ANYTHING. What would be a good way to tell them? I was thinking talking to my mom first and then have her bring it up to my dad when I'm not around and then I just have him bring it up when I get home. Help, please