Hi Karlfinno,
If you came to UK with a visit visa, you have to go back to the Philippines before your visa expired. You said, that you and your bf are planning to get married after you give birth, theres no problem with that. After you get married in the Philippines you can then apply for a spouse visa. You said you will go back to the Phils to renew your visa, If you plan to come back to UK as a visitor you can apply again for a visit visa ten days after you`ve arrived Manila. If you plan get married in the UK then you have to apply for a fiancee visa. About your question about renewing your visa, you can not renew your visa in the UK if its only a visit visa, you have to go back to the Philippines to apply again either for a visit or fiancee or spouse visa if you will get married in the Phils.
