I was just switched to orth tri cycle lo at the begining of this cycle by my doctor. I am almost to the end of my cycle, i'm supposed to start my period in 5 days. Before I was switched, I was on regular ortho tri cyclen for 4 years. I take my pill everyday at approx. The same time. I haven't missed any pills but I am feeling a few side effects that make me worry that I could be pregnant. About 3 days ago I had some very slight spotting. The blood was barely noticeable and was dark, like it was old blood. I have lately been feeling a little sick to my stomach. I have had sex a few times this month. Do you think its just the change in hormones that is making me feel this way and making me spot a little or do you think I could be pregnant? It is also possible that i'm worrying myself way to much but I would appreciate your opinions/advice.

Thanks!