Pregnant??

So I went off my birth control pills about 3 weeks ago because they were making me feel moody and awful. I’m married and have a 17 month old. We’re not really trying yet but would be over the moon if it happened. We had sec last weekend and today I’ve had some cramping with no sign of AF other than cramping. Earlier this week I had some lower abdominal pain so I’m wondering. Do you think I’m pregnant? What’s the earliest y’all got a positive test and what were your signs that you were pregnant before your missed period?