tubes tide 5yrs. ago/ 2days period then brown spotting w cramps

Ok ladies I have a question. About a week and a half ago my hubby and I noticed my boobs getting bigger and very very sore and my hips widening a bit. I have been nauseous at night and more recently almost everytime I eat. I have been really bloated. Me and my hubby have been ttc since Nov. and still nothing, but this time we were sure that we had been successful with all the symptoms I have been having. ( I don't normally have any of this with af) SO long story short I took a test a few days ago and a faint positive line appeared for about all of 5 seconds, and then dissappeared :( I figured the test was a dud or my hcg levels were too low, today around noon I started with a sharp back pain (not normal for af for me) and light cramping (I usually am sick in bed on day 1 of af) when I got home from work around 4 I had cm that had blood throughout it, it was stretchy but not alot. About an hour later I got a little more with a little more blood (light cramps and back pain still) And now, 2 hours later, it has turned brown still with a little cm (not alot) but the cramping has gone away and so hasn't the back pain!!!!!!!! All the other pregnancy symptoms are there still (sore breasts, nauseous feeling, bloating) Anyway me and my hubby are wondering if this could be implantation bleeding since its not like my usual af. Im just confused because everything I read says that implantation bleeding is only a spot or two :( ......I want to know your stories and what you know or have experienced!!!!! I don't want to read anymore websites!!!!!! I've read a ton!!!!!!!! Again sorry for the explicit detail but I just want the most accurate responses on what people think or have experienced!!!!!!!! THANK YOUUUU 

My tubes are tied, and my period is late. I want to know are there other symptoms/causes of a missed period, besides the pregnancy?