Could it be?

I think i might be pregnant but i'm not sure. I'm about 3 weeks late i think but i could be wrong because i was on the contraceptive injection and when i came off it my periods were all over the place so i'm really confused. Is it possible to be pregnant without getting any kind of morning sickness or sore breasts? I have other symptoms like i need to wee all the time and my breasts have definitely grown. Can anyone make this any clearer for me? I'd be really greatful x