5 weeks and have light cramping constantly

So I'm approx 5W2D and for the last week I've had cramping. At first the felt like AF was coming and my cycle has been out of whack recently so when I got negative results from cheapies, I didn't think much of it. But then last night they felt different so I used a more expensive test and it was positive, took another a few hours later, positive again.

Thing is, the cramps are consistent. They're very light with a bit of heartburn thrown in for good measure, but they're always there. I've tried to read up on it but everything seems to say that they come and go throughout the day, not consistently. Just want to know if anyone else has experienced this with early pregnancy and if it's anything to worry about.

I work a pretty physical job where I'm on my ferry for 10+ hours and do a lot of lifting so dont know if that's a contributing factor?