What Causes Spotting With Clots Instead Of Normal Menstruation?

period is always on time; however it came 5 days late. The first time i notice blood was when i used the bathroom, it was really like. the same day i monitored it and there was no blood on the pad for the next few hour. Went to sleep and woke up with blood on the pad but not that much. i notice when i pee i can see little clot in the toilet and when i take a shower i see these little thing. Its now my second/third day and theres no blood on the pad. Two weeks prior, ive been feeling a little weird, breasts were really tender, feeling bloated, sleeping more often and could smell a mile away. could it be im pregnant? The menstrual flow is not like how it usually is. Im puzzle!!! can u help