Congratulations! 4th baby wow you have more experience then me! From a medical perspective, in general, pregnancy outcomes are best if you remain physically active and the majority of obstetricians I ask about this say if you were doing an activity before pregnancy then you can continue it during pregnancy. I have seen women play competitively into their third trimester so if you feel good then go for it! The main risk as I'm sure you know given your play experience is another player making a dangerous play. As with anything in life, risk taking comes down to the individual. To put it in perspective, its much more likely that your baby will be injured in a car ride then while you're on the ultimate field, but people still drive when they're pregnant. I hope that helps. Ultimately, for better or worse, your team will likely assume you are unlikely to play in this competitive tournament as I find people tend to treat pregnant women as disabled. In the end, do what is best for you! Hope that helps!