If you don't want to fully go back early you may be able to bump up your earnings enough by using kit days if your employer agrees or by using your holidays either at the end of paid SMP or by ending SMP early and taking your accrued holiday - check the calculator online 😊
You’d definitely get maternity allowance
If you earn enough in your qualifying weeks you would get SMP. There is a calculator on gov website, that will tell you when your qualifying weeks are. You just need to make sure you earn over so much in those weeks, so may have to go back early to your SMP for next maternity leave xx