We just found out we're pregnant but I'm curious how far along I really am. I haven't been to the doctor yet for an…

We just found out we're pregnant but I'm curious how far along I really am. I haven't been to the doctor yet for an ultrasound but go in this week. Everyone tells me to go by the first day of my last cycle which would have been Nov 19 only thing is I'm not sure if I should consider that a cycle or not due to being on the depo shot for four years and not having a cycle at all up until the last year I'd have occasional spotting. I've never had regular cycles, but Nov 19th I woke up in a puddle of blood, cramping and all. Usually when I'd start it would be when I'd go to the restroom, that wasn't the case. After that I was off and on sick thinking it was just a virus going around but as soon as I told a friend it wasn't regular throw up that it was more of an acid she recommended i take a test. Took two tests both came out positive saying 3+ weeks which then we read the doctors would consider it 5-6 weeks. I had nausea all day for a good two weeks now it's not near as bad. I was told nausea goes away the second trimester that's why I'm curious if I'm really further along or if it's something else. Any ideas?