Need some kind words...?

I'm 4 months pregnant with baby #2 and I feel so "blue." I have a 2-year-old daughter that I love to death. I had her at 19 and it was an unplanned pregnancy but I was on the Pill to prevent it, not just sleeping around, being irresponsible. But I chose to step up, grow up, mature considerably and be a good parent. But people make me feel so lousy. Complete strangers as well as my co-workers tell me I should be ashamed for having a baby so young, not being married and making umptions about me like I'm slutty or poor or uneducated. None of those are true. My life revolves around my daughter and baby-on-the-way. I do right by them. I make (fairly) nutritious meals, I play with her one-on-one, take her to the park, read to her, keep her clean and take her to the doctor regularly. So why do I feel like such a bad parent? Ppl keep telling me my kids will pay for my mistakes. Is that true? I don't think of them as mistakes, more like blessings. Plz give me some encouragement, something!