I'm having the same issues at 3wks: very bad abdominal cramps on one side (with some other issues too - i.e., bad headaches, every few days lower back aches). When I went to the doctor he checked to make sure that the baby wasn't in my fallopian tubes. The baby wasn't in the tubes, but the pain was coming from the side where it is in my uterus. I'm waiting on the blood tests that they did to rule out anything else.
i had HORRIBLE back pains for 2-3 weeks. it got to the point that i couldn't walk and was having horrible a/f like cramps (mainly on one side or the other) so i went to the er to see what was wrong....turns out it wasn't a miscarriage from one baby. i was having twins and my symptoms were doubled. lol (the backpains are due to the way one of the babies is laying. right on my spine) which i was only 8 weeks along so the babies were only the size of peanuts. so it could be a m/c (God forbid) or it could be the way the baby is positioned. if it's laying on your spine....it's gonna hurt. trust me....i know. lol. the only way to know for sure is to go to the doctors. have them do an u/s and check your hcg levels.
It really depends, as signs for ectopic pregnancies are cramping and sharp pains in the pelvic area on one side or both. Although, I had the same cramping, menstrual like back aches and sharp pelvic pain. I was being treated as If I was having an ectopic, but at 5w5d they found the gestational sac and the 2 yolk sacs. I think you should go get checked out to make sure that your fallopian tubes are clean and free of any embryo.
They should be able to see a gestational sac by now, and dont be worried if they dont see the baby or a yolk sac yet, it took a long time to be able to see mine. They havent seen my babies yet, but it is still to early.
Take it easy, make sure to get rest and keep hydrated. Here are some other symptoms of ectopic pregnancies. BUT don't be fooled because a lot of the ectopic symptoms tend to be normal pregnancy symptoms aswell.
Bleeding or spotting
Pain in one or both sides
Pain in the abdomen
nausea and vomitting
dizziness and or fainting
The dizziness, fainting and shoulder pain are all signs of your tube possibly rupturing. Id say go see your doc and make sure your okay, its better to be safe than sorry. Ectopic pregnancies is the main issue for pregnancy deaths in the mothers.