Thankyou for the enquiry,
You should clear your all doubt regarding the pregnancy.The guy 2 is very likely to be the father of your baby.The reasons which i give are:
1) The ovulation time for you is very much matching with the conceptional date.The guy two just pulled out but it doesn't prevent pregnancy as i told that the pregnancy is possible even with pre-cum.The pulling out method is not a recommended method of contraception.If the guy 2 would have used condoms then i could have gone for guy one.for the possible father.
2) The plan B drug can be taken withing 72 hrs and is effective if you take it withing 72 hrs after intercourse.Since you have taken it withing 3 days so the abortion may have resulted if there would have been any pregnancy dur to guy one.
3) The periods from 4/15/to 4/18 is likley to be the side effect of the drug plan b.The miscarriage would have resulted if there was any pregnancy.
4)The sonographic age of the foetus mathes exactly with the guy 2 causing pregnancy in you and alos your expected ovulation time.
The DNA pre-natal paternity tests are availbale at around 14 weeks of pregnancy by doing aminocentesis or cv sampling.You may try this if you feel any doubt.
Please visit here for more information:
pre-natal paternity testing
Let me know if you have any doubt.