I don't know anything, please help

Tabitha

My last period started March 15th, my next period was suppose to start April 16th. I got cramps on the second day of my "period" so I thought I was going to start, but didn't and took a pregnancy test on April 20th and April 21st and they both came out positive. According to the <a href="https://play.google.com/store/apps/details?id=com.glow.android">glow app</a> I'm about 5 weeks pregnant, but I'm having cramps, is that normal? Also at how many weeks do things start to happen, like when will I get morning sickness and the food cravings and everything else people feel in the beginning of their pregnancy? I really don't know anything about pregnancies and I don't have anyone to talk to about it, please help.