It is extremely unlikely that you would be pregnant from sex with someone who did not ejaculate inside your vagina or anywhere near your vaginal opening. It sounds like the person you cheated with ejaculated inside your mouth, if that’s what you mean by giving him a blow job “the rest of the way.” It takes sperm meeting with an egg to begin a pregnancy and it does not sound like you got any of that person’s sperm inside your vagina.
It is much more likely that your husband impregnated you since he ejaculated inside of your vagina. Of course, the only 100% certain way is to do paternity testing later on after the baby is born.
Confide In Someone
It sounds like you may be experiencing some stress or anxiety related to whose sperm resulted in your pregnancy. As you look toward the rest of your pregnancy, try to relax, keep your ob/gyn visits (for the healthiest pregnancy possible), and talk with your ob/gyn about any pregnancy or personal health related questions you may have. Your doctor or nurse can also give you recommendations for lifestyle choices, such as healthy eating and safe exercise, to support a healthy pregnancy.
If you experience any difficult stress, anxiety, or depression, you can find a counselor through apa.org. It may help to talk about your concerns, as well as any relationship issues you may be experiencing, with a counselor or therapist.
Be Careful Of STDs
If you are still having sex with people other than your husband (or if you are having sex with your husband, and think or know that he is having sex with other people), it would be wise to use a condom or other barrier method to protect the fetus from sexually transmitted infections. You might also ask your doctor or nurse about testing for sexually transmitted infection, which is often but not always offered to pregnant women. I hope that you are feeling supported throughout your pregnancy and able to access the kinds of healthcare that will support you and your growing family. Best wishes to you.