What Causes Vaginal Spotting With Stomach Cramps?

since about january of this year my periods went haywire. I was bleeding for weeks at a time with no more than a 4 day break before bleeding again. At the beginning of the month me and my boyfriend had intercourse during one of the 4 days that i wasnt bleeding and since then i have not bled heavily. But within the past week i have been spotting. Light pink but only when i wipe after using the restroom. I have had mild cramping, lower back aches and my breasts are tender. Yess, i do see that these are signs of pregnancy but with my wild and crazy period i do not kno wut to think. Before my periods went crazy i always got my period at the end of the month. I have a couple more days before i can say a missed period. Could i be pregnant?