Am I pregnant?

Hey ladies, I'm new to the group and I've been doing a lot of reading on all different sites and I'm still so lost, I'm losing my mind! I just got married in Feb, me and my now husband have been together since I was 14, I'm now 18, since he's gotten out of basic and we got married we have been having unprotcted sex and now I'm questioning if I'm pregnant or not. About a week ago my nipples started to become really sensitive, like even just wearing a shirt without a bra hurts them and I've been having these constant dull, sometimes sharp, cramps in my stomach and my lower back, I do have sciatica in my lower right side of my back and it hasnt bothered me for a LONG time up a couple days ago, my husband claims my nipples are "darker" now, I had pink nipples and now they're more browny, I guess, haha. I have taken 3 test, the first one I took was a cheap one from the gas station on post and it came out positive but not right away, it looked negative at first so I walked away and then when I looked back I could see a very faint blue line SO I bought 2 clear blue test and I dont know if it's my mind hoping and going crazy or not but I swear I see a VERY faint line, Im not too sure though, I've been reading a lot about evap lines but the test I took today i think I saw the faint line pop up within the 3 minutes wait time, it looks a little blue to me at the top but I can't really tell, my husband is in the field now so I can't ask for his opinion so I thought I'd ask you lovely ladies what you thought? i will try to post pictures when I get back to my apartment, it would mean the world to me if anyome could give me some advice, I'm still a baby myself, just moved out and all!