I tested using a Clear Blue test which was positive on 2 occasions.
I have been to at least 4 pregnancy scans.
I did 2 urine strip tests which both came out negative.

Could I be pregnant or could it have been a missed-period miscarriage?

How late are you for your period, and exactly what point of the day were you taking these tests?

You HAVE to take them right after you wake up , and you have to do it the first time you pee that day. You also have to read it only within the time frame given... not much later or too soon.

Otherwise the results are inconclusive and you have to try again the next moring.

It's possible you had been pregnant, hence positives tests, but had an early loss. Much depends on when you tested, the span of time between tests, sensitivity of the tests, when you had the scans, etc. It's also possible you mistakenly read test results, again depending on how the test directions were followed.

If you've had four scans, which would normally be spaced out at least a week apart, and unusual to have so many for confirming a pregnancy, and there is no indication of a pregnancy, you wouldn't be pregnant.

I agree with Doula 100%, had to spread the rep.

You stated that you've had 4 scans. I don't know of a single doctor that would order back to back scans just to confirm a pregnancy, when the first one showed you weren't pregnant. Unless you're paying for them to do more than is advised, and I know they aren't cheap, no doctor would do more than one a week, which would mean that at the very least you've had 4 scans in a month, and no sign of pregnancy. I didn't have 4 scans total for both of my pregnancies, it's not recommended. I was given one at 6 months, and the second one was only because they were worried about the amount of amniotic fluid, and that scan was done a week before my baby was due. With my second I had only one scan my entire pregnancy. With my third I had a scan at 3 months because I was bleeding heavily and they wanted to know what was going on. I miscarried that baby.

At home pregnancy tests can be tricky, a lot of people don't read or follow the directions, they're in too much of a hurry, think they just have to pee on the stick, and don't read how to do it all correctly. False positives are rare, but they do happen.

Sadly there's really no way to tell you if you miscarried, or if you were ever pregnant. The doctors can't even tell you that. I would say that you're not pregnant now, because after 4 scans and the two negative tests you've had, a pregnancy would definitely show up by now.

Unless the info you posted here is incorrect, or you wrote it out wrong.

So just to be sure, how late is your period? How soon after a missed period did you take the two tests that showed positive? When you say scan, what do you mean? When was your last period? How old are you (it does matter because younger women often have periods that are off for many years before they become regular)? Have you had a period or any bleeding since the positive test results?