Thank you for posting, Whitepaper. Welcome to the Dreams forum.
Pregnant women often have unusual dreams. There's so much going on physiologically, psychologically, that the emotions will be affected and play out in our dreams. Deep-seated fears, worries, unresolved issues but also spiritual communication come through in dreams, especially during this very blessed time of life.
Sometimes, it is best to let go of nonsensical dreams one has when one is ill, feverish because the dreams can be so disjointed that to interpret them would cause confusion rather than create clarity. It isn't that these dreams don't "mean anything" because they do (they spring from your own subconscious!) but it is like trying to straight out and follow a huge tangled mess of yarn. While the symbols may hold meaning, they are small and insignificant to your overall life so most often, it is not worth the effort to untangle those types of dreams.
However, I can shed a little light for you here since the dreams have been troubling you:
It is extremely common for pregnant women to dream about miscarriage, not being pregnant or even having sex with another man. No need for guilt because none of these scenarios are serious wishful thoughts. Mostly, they are based in worries.
Listen, having a child is a life-altering experience. One can't be a little pregnant. You're pregnant. You're having a baby. There's no turning back the clock. Women can be nervous about this new, uncharted journey. A lot of women often scream out, "No! I changed my mind! I don't want to do this!" when they begin labor.
Dreaming about sex with another man is a way for your mind to express this.
Attending a wedding party often represents an upcoming change in life. Good news is that you were happy and having a good time which indicates that generally, you're enjoying this present time of your life, at least when you're around others. But when you're alone, you might have second thoughts. You feel horrible about having second thoughts but you do have them.
The plastic toys that came out along with the placental blood seems to me to indicate that the idea of being pregnant and having a baby was like fun and games to you but the reality of having a real baby...well, you don't know if you're ready for that yet and you don't want others to know about these thoughts.
Once you recognize your own doubts, it's hard to go back to the party to be happy and joyous again because, well, you have concerns.
Please don't worry. Especially about this dream. It is your subconscious mind's way of releasing very understandable and very common worries of many pregnant women.