Hi Isabella, hope you’re doing well! Speaking from personal experience, I had the lecture before the lab and had other friends that had it the way you did and found that overall, there wasn’t that much of a difference. 
Here’s a quick description of the lab and lecture: I found that the lab lecture provided some clarity as to what would be occurring during the actual lab and then described what the analysis would look like for the post-lab. During the actual lab time, we were given a rundown of the experiment by the GSI (graduate student instructor) prior to starting the actual lab. Also, any extra time was open for us to either leave or stay there and complete the analysis. 
The pros to having the lecture prior to the lab would include knowing what you’re headed into before heading into it and being prepared for it. However, make sure to take good notes to refer back to during the post-lab work-up as it’ll be easier to handle. 
I personally think your schedule would be perfectly fine and there’s no need to stress about changing it. Here are some suggestions for you when it comes to tackling your chem lab schedule: prior to going into the lab, make sure to read through the experiment description which the instructors usually post beforehand. Then, during your lab lecture time, make sure to pay attention and follow exactly what the instructor is pointing out as they tend to point out key information that you can include in your post-lab analysis. 
Overall, I wouldn’t stress about trying to fit the lecture before the lab, but if you feel like you would benefit from it, go ahead and see if there’s an open spot. I hope this helps! Feel free to follow up on this Q&A post or make another post if you have any further questions!
Best,
Bushra, PMH Advisor