I think if you are OK with adoption then there is no need to have a kid with someone you're not going to marry. Remember, you will be bound to this man ( your sperm donor) for the rest of your life. With adoption you get the child without the hassle (child birth, possibly useless baby daddy). You also get to keep your figure 🙂 You can choose to adopt a child later in life, when you feel more comfortable with the idea of being a mother. I would not recommend bringing a child into this world if you do not want to . You cannot return an unwanted child. Don't have a child just to try and see what it's going to be like, or to please your family. Remember you will be the one responsible for raising this child, NOT THEM.
Before you decide to have a child (biological or adoption) I would suggest spending some time with friends and family with kids to see how they manage these things. Remember, kids grow up eventually. They will not remain infants, toddlers or teenagers forever. If you raise your child to be independent you will not feel like you need to provide them with everything 100% of the time. They might surprise you and stand on their on feet by the time they hit 18, and you'll be left wondering where the time went.
Usiruhusu mtu akulazimishe kuzaa, hata kama ni wazazi wako. If it bugs them more than it bugs you that's their problem, not yours.