Honestly try not to worry, cramping is totally normal, especially if it's not your first pregnancy, the cramping can get pretty intense and doesn't always feel like stretching pain, with my 4th I was cramping so bad, just like I do on my period, in my back and everything. I was constantly on knicker watch for the first 12 weeks until the scan. Feeling like you are about to/or just have come on is also normal in the early weeks, you get more swollen down there and heavier discharge which makes it feel like your period is going to arrive any second.
Symptoms wise, most pregnancies don't give any or have intermittant symptoms until around 7-9 weeks, some don't give any at all, some give you lots of symptoms before AF is even due.
In regards to the tests, as a previous poster has said, chemical pregnancies, the lines tend to be faint to start with then get even lighter, I've had around 6 chemical pregnancies while TTC my last two babies. My two confirmed miscarriages, one spontanious at 6.5w and one MMC, the tests had good clear progression on them both times, in fact with my MMC I was still getting super dark tests for weeks after the ERPC which was done at 10.5 weeks, I also cruelly had all the symptoms under the sun with my MMC too, I was pretty ill with morning sickness sat in the hospital waiting to have the pregnancy removed. The tests with that pregnancy were far darker than the tests I got with my current pregnancy (34 weeks now). Although I have to say, the only thing that made me suspicious that things wern't progressing as they should was that my cramping got less intense around 8 weeks when it's usually peaking for me around then, and then it almost vanished, so I booked a private scan which I just knew wasn't going to give good news. The one consistent symptom I've had with all of my successful pregnancies was the cramping which got worse up to around 8-9 weeks before it started getting less frequent.
On the flip side, one of my successful pregnancies had no symptoms at all apart from a few days of queasiness before my period was due, then it vanished and never returned, no sore boobs, no tiredness etc, only thing I had was the cramping. All pregnancies are different so try not to worry. I've had all kinds of combos through 8 pregnancies (5 births, 2 MC and the pregnancy I'm carrying now). I understand why you are worrying though, I didn't worry at all until my first miscarriage, since then I've been a serial tester in all the pregnancies since, my first 4 I just took 1 test to confirm pregnancy then didn't give it a second thought.
You are pregnant, Congratulations! 